Fix integration test failures

First, improve error output by adding descriptive messages to snafu
error types.

Second, add the ability to call the WASM guest application in the
runner via the set_name and hello entrypoint functions.

Then, fix the following bugs:

 - Only wrap (trampoline) instance-type exports, other types are
   exported with similar names.
 - Find exports in the "front instance" using an interface name lookup,
   then function lookup (previously: only func name).
 - Run post_return methods on WASM func calls after exit from
   trampoline, otherwise the same instance cannot be used again.

Author: dylanplecki

Cargo.toml

@@ -30,7 +30,9 @@ anyhow = "1"
 derivative = "2"
 semver = "1"
 wasmtime = { version = "33", features = ["component-model"] }
-wit-bindgen = "0.42"
+wit-bindgen = { version = "0.42", default-features = false, features = [
+  "macros",
+]}
 
 [target.'cfg(unix)'.dependencies]
 anyhow.workspace = true

tests/wasm/application/Cargo.toml

@@ -6,5 +6,13 @@ edition.workspace = true
 [lib]
 crate-type = ["cdylib"]
 
+[features]
+default = [
+    "async"
+]
+async = [
+    "wit-bindgen/async",
+]
+
 [dependencies]
 wit-bindgen.workspace = true

tests/wasm/kvstore/Cargo.toml

@@ -6,5 +6,13 @@ edition.workspace = true
 [lib]
 crate-type = ["cdylib"]
 
+[features]
+default = [
+    "async"
+]
+async = [
+    "wit-bindgen/async",
+]
+
 [dependencies]
 wit-bindgen.workspace = true

tests/wasm/logger/Cargo.toml

@@ -6,5 +6,13 @@ edition.workspace = true
 [lib]
 crate-type = ["cdylib"]
 
+[features]
+default = [
+    "async"
+]
+async = [
+    "wit-bindgen/async",
+]
+
 [dependencies]
 wit-bindgen.workspace = true