[KeyVault] - Cryptography client refactoring (Azure#14077)

## What

This PR does a pure refactor of local cryptography from the existing implementation
to provide some flexibility for upcoming AES algorithms and allow for a cleaner separation
of concerns between local / remote providers.

## Why

The existing implementation worked well but I hit a few bumps when trying to add support
for AES algorithms which require different parameters crypto providers to conform to the 
same API our top-level clients do and allows for ease of extensibility when AES algorithms 
are added in the future.

## High level changes

- Replaced the crypto algorithms with a crypto provider interface that supplies a common set of operations
- Top level crypto client maintains a list of "providers" which are responsible for the crypto operations. Each provider isn't aware of other providers and the crypto client is responsible for sending the request to the right one.
- Centralized validation to top-level client.

Resolves Azure#14129

Author: maorleger

sdk/keyvault/keyvault-keys/CHANGELOG.md

@@ -6,6 +6,7 @@
 - Added `curve` to `createKeyOptions` to be used when creating an `EC` key.
 - Deprecated the current `encrypt` and `decrypt` methods in favor of the more flexible overloads that take an `{Encrypt|Decrypt}Parameters` and allow passing in algorithm specific parameters. This enables support for the various AES algorithms used in Managed HSM. The deprecated methods continue to function and there's no timeline for their removal.
 - Added `additionalAuthenticatedData`, `iv`, and `authenticationTag` to `EncryptResult` in order to support AES encryption and decryption.
+- Refactored the various cryptography providers and updated the error messages to be clearer and more descriptive.
 
 ## 4.2.0-beta.3 (2021-02-09)
 

sdk/keyvault/keyvault-keys/package.json

@@ -36,8 +36,8 @@
   "browser": {
     "os": false,
     "process": false,
-    "./dist-esm/keyvault-keys/src/localCryptography/algorithms.js": "./dist-esm/keyvault-keys/src/localCryptography/algorithms.browser.js",
-    "./dist-esm/keyvault-keys/src/localCryptography/hash.js": "./dist-esm/keyvault-keys/src/localCryptography/hash.browser.js"
+    "./dist-esm/keyvault-keys/src/cryptography/hash.js": "./dist-esm/keyvault-keys/src/cryptography/hash.browser.js",
+    "./dist-esm/keyvault-keys/src/cryptography/rsaCryptographyProvider.js": "./dist-esm/keyvault-keys/src/cryptography/rsaCryptographyProvider.browser.js"
   },
   "scripts": {
     "audit": "node ../../../common/scripts/rush-audit.js && rimraf node_modules package-lock.json && npm i --package-lock-only 2>&1 && npm audit",