Add override keyword in codebase (#120755)

For #120675

This uses a script to add the override keyword to places that need it in the codebase

Note that we can't enable the --noImplicitOverride setting yet since there are still around 200 errors that require further attention

src/vs/workbench/api/common/extHostTreeViews.ts

@@ -749,7 +749,7 @@ class ExtHostTreeView<T> extends Disposable {
 		this.nodes.clear();
 	}
 
-	dispose() {
+	override dispose() {
 		this._refreshCancellationSource.dispose();
 
 		this.clearAll();