Simplify logic for webview resource uris (#123740)

* Simplify logic for webview resource uris

This change attempts to simplify the logic around webview resource uris by doing the following:

- Hard code the resource origin. We always will be hitting a service worker for these paths so they don't need to be dynamic (although in the future we may want to pull them from `product.json`)

    This lets us remove these properties from the environment service

- Move remote handling from the resource loader in `asWebviewUri`.

- Remove the handling of http and https paths from the resource loader.

    I don't think these cases can be hit any longer (although I need to confirm this with more testing for the web case). Instead I added a check to `asWebviewUri` so that we return the original uri if a http(s) uri is passed in

* Restore normalizeResourcePath

We still need to convert between a remote uri and one that our remote file system can read

* Fix test

* Restore passing in remote on extension side

* Remove only

src/vs/workbench/api/common/extHost.protocol.ts

@@ -74,8 +74,6 @@ export interface IEnvironment {
 	extensionTestsLocationURI?: URI;
 	globalStorageHome: URI;
 	workspaceStorageHome: URI;
-	webviewResourceRoot: string;
-	webviewCspSource: string;
 	useHostProxy?: boolean;
 }