implement browser clipboard service (#75293)

* implement browser clipboard service

* actually register the clipboard service

* update all refs to newly async funcs

* addressing comments

* small fixes

* all asyncs as a result of readText

* fix unit test

* cleanup for writeText refs

* cleanup and reduce diff noise

* qfix

* address feedback

src/vs/workbench/api/browser/mainThreadClipboard.ts

@@ -20,11 +20,10 @@ export class MainThreadClipboard implements MainThreadClipboardShape {
 	}
 
 	$readText(): Promise<string> {
-		return Promise.resolve(this._clipboardService.readText());
+		return this._clipboardService.readText();
 	}
 
 	$writeText(value: string): Promise<void> {
-		this._clipboardService.writeText(value);
-		return Promise.resolve();
+		return this._clipboardService.writeText(value);
 	}
 }