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/p-try/index.js

@@ -0,0 +1,9 @@
+'use strict';
+
+const pTry = (fn, ...arguments_) => new Promise(resolve => {
+	resolve(fn(...arguments_));
+});
+
+module.exports = pTry;
+// TODO: remove this in the next major version
+module.exports.default = pTry;