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/core-js/modules/es.array.is-array.js

@@ -0,0 +1,9 @@
+'use strict';
+var $ = require('../internals/export');
+var isArray = require('../internals/is-array');
+
+// `Array.isArray` method
+// https://tc39.es/ecma262/#sec-array.isarray
+$({ target: 'Array', stat: true }, {
+  isArray: isArray
+});