Adopt the MSAL broker to talk to the OS for Microsoft auth (#233739)

This adopts the `NativeBrokerPlugin` provided by `@azure/msal-node-extensions` to provide the ability to use auth state from the OS, and show native auth dialogs instead of going to the browser.

This has several pieces:
* The adoption of the broker in the microsoft-authentication extension:
  * Adding `NativeBrokerPlugin` to our PCAs
  * Using the proposed handle API to pass the native window handle down to MSAL calls (btw, this API will change in a follow up PR)
  * Adopting an AccountAccess layer to handle:
    * giving the user control of which accounts VS Code uses
    * an eventing layer so that auth state can be updated across multiple windows
* Getting the extension to build properly and only build what it really needs. This required several package.json/webpack hacks:
  * Use a fake keytar since we don't use the feature in `@azure/msal-node-extensions` that uses keytar
  * Use a fake dpapi layer since we don't use the feature in  `@azure/msal-node-extensions` that uses it
  * Ensure the msal runtime `.node` and `.dll` files are included in the bundle
* Get the VS Code build to allow a native node module in an extension: by having a list of native extensions that will be built in the "ci" part of the build - in other words when VS Code is building on the target platform

There are a couple of followups:
* Refactor the `handle` API to handle (heh) Auxiliary Windows https://github.com/microsoft/vscode/issues/233106
* Separate the call to `acquireTokenSilent` and `acquireTokenInteractive` and all the usage of this native node module into a separate process or maybe in Core... we'll see. Something to experiment with after we have something working. NEEDS FOLLOW UP ISSUE

Fixes https://github.com/microsoft/vscode/issues/229431

extensions/microsoft-authentication/tsconfig.json

@@ -22,6 +22,7 @@
 	"include": [
 		"src/**/*",
 		"../../src/vscode-dts/vscode.d.ts",
-		"../../src/vscode-dts/vscode.proposed.idToken.d.ts"
+		"../../src/vscode-dts/vscode.proposed.idToken.d.ts",
+		"../../src/vscode-dts/vscode.proposed.nativeWindowHandle.d.ts"
 	]
 }