[release] tools/goplssetting: handle changes in gopls setting structure

This CL handles the various changes in my current stack of gopls CLs
and it shouldn't be merged until CL 280355 is merged. It handles the
new gopls settings hierarchies, maps keyed by enums, and changes to
default values.

I was struggling to work with the method writing out the lines directly,
so I switched to a JSON struct. This works fine in most cases, except
when writing out the default values. I think gopls should probably
produce interface{} for default values, but that will need to be dealt
with later. For now, I added a relatively basic work-around.

Change-Id: Ie4b69074f1bf02023fa39488ebc1c5c9660a03fc
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/279728
Run-TryBot: Rebecca Stambler <rstambler@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Trust: Rebecca Stambler <rstambler@golang.org>
Trust: Hyang-Ah Hana Kim <hyangah@gmail.com>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
(cherry picked from commit de64eaa)
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/282372
Run-TryBot: Hyang-Ah Hana Kim <hyangah@gmail.com>

Author: stamblerre

docs/settings.md

@@ -79,7 +79,7 @@ Default: `false`
 
 ### `go.buildFlags`
 
-Flags to `go build`/`go test` used during build-on-save or running tests. (e.g. ["-ldflags='-s'"]) This is propagated to the language server if `gopls.buildFlags` is not specified.
+Flags to `go build`/`go test` used during build-on-save or running tests. (e.g. ["-ldflags='-s'"]) This is propagated to the language server if `gopls.build.buildFlags` is not specified.
 
 ### `go.buildOnSave`
 
@@ -91,7 +91,7 @@ Default: `package`
 
 ### `go.buildTags`
 
-The Go build tags to use for all commands, that support a `-tags '...'` argument. When running tests, go.testTags will be used instead if it was set. This is propagated to the language server if `gopls.buildFlags` is not specified.
+The Go build tags to use for all commands, that support a `-tags '...'` argument. When running tests, go.testTags will be used instead if it was set. This is propagated to the language server if `gopls.build.buildFlags` is not specified.
 
 Default: ``
 
@@ -576,76 +576,26 @@ Default: `package`
 
 Configure the default Go language server ('gopls'). In most cases, configuring this section is unnecessary. See [the documentation](https://github.com/golang/tools/blob/master/gopls/doc/settings.md) for all available settings.
 
-#### `allowImplicitNetworkAccess`
+#### `build.allowImplicitNetworkAccess`
 (Experimental) allowImplicitNetworkAccess disables GOPROXY=off, allowing implicit module
 downloads rather than requiring user action. This option will eventually
 be removed.
 
 
-#### `allowModfileModifications`
+#### `build.allowModfileModifications`
 (Experimental) allowModfileModifications disables -mod=readonly, allowing imports from
 out-of-scope modules. This option will eventually be removed.
 
 
-#### `analyses`
-analyses specify analyses that the user would like to enable or disable.
-A map of the names of analysis passes that should be enabled/disabled.
-A full list of analyzers that gopls uses can be found [here](analyzers.md)
-
-Example Usage:
-```json5
-...
-"analyses": {
-  "unreachable": false, // Disable the unreachable analyzer.
-  "unusedparams": true  // Enable the unusedparams analyzer.
-}
-...
-```
-
-
-#### `annotations`
-(Experimental) annotations suppress various kinds of optimization diagnostics
-that would be reported by the gc_details command.
- * noNilcheck suppresses display of nilchecks.
- * noEscape suppresses escape choices.
- * noInline suppresses inlining choices.
- * noBounds suppresses bounds checking diagnostics.
-
-
-#### `buildFlags`
+#### `build.buildFlags`
 buildFlags is the set of flags passed on to the build system when invoked.
 It is applied to queries like `go list`, which is used when discovering files.
 The most common use is to set `-tags`.
 
 If unspecified, values of `go.buildFlags, go.buildTags` will be propagated.
 
 
-#### `codelenses`
-codelenses overrides the enabled/disabled state of code lenses. See the "Code Lenses"
-section of settings.md for the list of supported lenses.
-
-Example Usage:
-```json5
-"gopls": {
-...
-  "codelens": {
-    "generate": false,  // Don't show the `go generate` lens.
-    "gc_details": true  // Show a code lens toggling the display of gc's choices.
-  }
-...
-}
-```
-
-
-#### `completionBudget`
-(For Debugging) completionBudget is the soft latency goal for completion requests. Most
-requests finish in a couple milliseconds, but in some cases deep
-completions can take much longer. As we use up our budget we
-dynamically reduce the search scope to ensure we return timely
-results. Zero means unlimited.
-
-
-#### `directoryFilters`
+#### `build.directoryFilters`
 directoryFilters can be used to exclude unwanted directories from the
 workspace. By default, all directories are included. Filters are an
 operator, `+` to include and `-` to exclude, followed by a path prefix
@@ -659,11 +609,11 @@ Include only project_a: `-` (exclude everything), `+project_a`
 Include only project_a, but not node_modules inside it: `-`, `+project_a`, `-project_a/node_modules`
 
 
-#### `env`
+#### `build.env`
 env adds environment variables to external commands run by `gopls`, most notably `go list`.
 
 
-#### `expandWorkspaceToModule`
+#### `build.expandWorkspaceToModule`
 (Experimental) expandWorkspaceToModule instructs `gopls` to adjust the scope of the
 workspace to find the best available module root. `gopls` first looks for
 a go.mod file in any parent directory of the workspace folder, expanding
@@ -672,16 +622,7 @@ found, gopls will check if there is exactly one child directory containing
 a go.mod file, narrowing the scope to that directory if it exists.
 
 
-#### `experimentalDiagnosticsDelay`
-(Experimental) experimentalDiagnosticsDelay controls the amount of time that gopls waits
-after the most recent file modification before computing deep diagnostics.
-Simple diagnostics (parsing and type-checking) are always run immediately
-on recently modified packages.
-
-This option must be set to a valid duration string, for example `"250ms"`.
-
-
-#### `experimentalPackageCacheKey`
+#### `build.experimentalPackageCacheKey`
 (Experimental) experimentalPackageCacheKey controls whether to use a coarser cache key
 for package type information to increase cache hits. This setting removes
 the user's environment, build flags, and working directory from the cache
@@ -691,65 +632,129 @@ by an experiment because caching behavior is subtle and difficult to
 comprehensively test.
 
 
-#### `experimentalWorkspaceModule`
+#### `build.experimentalWorkspaceModule`
 (Experimental) experimentalWorkspaceModule opts a user into the experimental support
 for multi-module workspaces.
 
 
-#### `gofumpt`
+#### `formatting.gofumpt`
 gofumpt indicates if we should run gofumpt formatting.
 
 
-#### `hoverKind`
-hoverKind controls the information that appears in the hover text.
-SingleLine and Structured are intended for use only by authors of editor plugins.
+#### `formatting.local`
+local is the equivalent of the `goimports -local` flag, which puts
+imports beginning with this string after third-party packages. It should
+be the prefix of the import path whose imports should be grouped
+separately.
 
 
-#### `importShortcut`
-importShortcut specifies whether import statements should link to
-documentation or go to definitions.
+#### `ui.codelenses`
+codelenses overrides the enabled/disabled state of code lenses. See the
+"Code Lenses" section of the
+[Settings page](https://github.com/golang/tools/blob/master/gopls/doc/settings.md)
+for the list of supported lenses.
 
+Example Usage:
 
-#### `linkTarget`
-linkTarget controls where documentation links go.
-It might be one of:
+```json5
+"gopls": {
+...
+  "codelens": {
+    "generate": false,  // Don't show the `go generate` lens.
+    "gc_details": true  // Show a code lens toggling the display of gc's choices.
+  }
+...
+}
+```
 
-* `"godoc.org"`
-* `"pkg.go.dev"`
 
-If company chooses to use its own `godoc.org`, its address can be used as well.
+#### `ui.completion.completionBudget`
+(For Debugging) completionBudget is the soft latency goal for completion requests. Most
+requests finish in a couple milliseconds, but in some cases deep
+completions can take much longer. As we use up our budget we
+dynamically reduce the search scope to ensure we return timely
+results. Zero means unlimited.
 
 
-#### `linksInHover`
-linksInHover toggles the presence of links to documentation in hover.
+#### `ui.completion.matcher`
+(Advanced) matcher sets the algorithm that is used when calculating completion
+candidates.
 
 
-#### `local`
-local is the equivalent of the `goimports -local` flag, which puts imports beginning with this string after 3rd-party packages.
-It should be the prefix of the import path whose imports should be grouped separately.
+#### `ui.completion.usePlaceholders`
+placeholders enables placeholders for function parameters or struct
+fields in completion responses.
 
 
-#### `matcher`
-matcher sets the algorithm that is used when calculating completion candidates.
+#### `ui.diagnostic.analyses`
+analyses specify analyses that the user would like to enable or disable.
+A map of the names of analysis passes that should be enabled/disabled.
+A full list of analyzers that gopls uses can be found
+[here](https://github.com/golang/tools/blob/master/gopls/doc/analyzers.md).
 
+Example Usage:
 
-#### `semanticTokens`
-(Experimental) semanticTokens controls whether the LSP server will send
-semantic tokens to the client.
+```json5
+...
+"analyses": {
+  "unreachable": false, // Disable the unreachable analyzer.
+  "unusedparams": true  // Enable the unusedparams analyzer.
+}
+...
+```
+
+
+#### `ui.diagnostic.annotations`
+(Experimental) annotations specifies the various kinds of optimization diagnostics
+that should be reported by the gc_details command.
+
+
+#### `ui.diagnostic.experimentalDiagnosticsDelay`
+(Experimental) experimentalDiagnosticsDelay controls the amount of time that gopls waits
+after the most recent file modification before computing deep diagnostics.
+Simple diagnostics (parsing and type-checking) are always run immediately
+on recently modified packages.
+
+This option must be set to a valid duration string, for example `"250ms"`.
 
 
-#### `staticcheck`
+#### `ui.diagnostic.staticcheck`
 (Experimental) staticcheck enables additional analyses from staticcheck.io.
 
 
-#### `symbolMatcher`
-symbolMatcher sets the algorithm that is used when finding workspace symbols.
+#### `ui.documentation.hoverKind`
+hoverKind controls the information that appears in the hover text.
+SingleLine and Structured are intended for use only by authors of editor plugins.
 
 
-#### `symbolStyle`
-symbolStyle controls how symbols are qualified in symbol responses.
+#### `ui.documentation.linkTarget`
+linkTarget controls where documentation links go.
+It might be one of:
+
+* `"godoc.org"`
+* `"pkg.go.dev"`
+
+If company chooses to use its own `godoc.org`, its address can be used as well.
+
+
+#### `ui.documentation.linksInHover`
+linksInHover toggles the presence of links to documentation in hover.
+
+
+#### `ui.navigation.importShortcut`
+importShortcut specifies whether import statements should link to
+documentation or go to definitions.
+
+
+#### `ui.navigation.symbolMatcher`
+(Advanced) symbolMatcher sets the algorithm that is used when finding workspace symbols.
+
+
+#### `ui.navigation.symbolStyle`
+(Advanced) symbolStyle controls how symbols are qualified in symbol responses.
 
 Example Usage:
+
 ```json5
 "gopls": {
 ...
@@ -759,8 +764,9 @@ Example Usage:
 ```
 
 
-#### `usePlaceholders`
-placeholders enables placeholders for function parameters or struct fields in completion responses.
+#### `ui.semanticTokens`
+(Experimental) semanticTokens controls whether the LSP server will send
+semantic tokens to the client.
 
 
 #### `verboseOutput`