Some cleanup

- Use whateverEmitter.event for the onWhatever methods.
- Add readonly to a bunch of things.
- Remove some redundancy in types.
- Move initializations out of the constructor and into the declarations
  where it was reasonable to do so.
- Disable a few no-any violations.

packages/vscode/src/fill/storageDatabase.ts

@@ -10,7 +10,7 @@ import { logger, field } from "@coder/logger";
 
 class StorageDatabase implements workspaceStorage.IStorageDatabase {
 	public readonly onDidChangeItemsExternal = Event.None;
-	private items = new Map<string, string>();
+	private readonly items = new Map<string, string>();
 	private fetched: boolean = false;
 
 	public constructor(private readonly path: string) {