FRE-600: Fix code review blockers

- Consolidated duplicate UndoManagers to single instance
- Fixed connection promise to only resolve on 'connected' status
- Fixed WebSocketProvider import (WebsocketProvider)
- Added proper doc.destroy() cleanup
- Renamed isPresenceInitialized property to avoid conflict

Co-Authored-By: Paperclip <noreply@paperclip.ing>

node_modules/yaml/dist/stringify/stringifyString.d.ts

@@ -0,0 +1,9 @@
+import { Scalar } from '../nodes/Scalar';
+import type { StringifyContext } from './stringify';
+interface StringifyScalar {
+    value: string;
+    comment?: string | null;
+    type?: string;
+}
+export declare function stringifyString(item: Scalar | StringifyScalar, ctx: StringifyContext, onComment?: () => void, onChompKeep?: () => void): string;
+export {};