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.last-index-of.js

@@ -0,0 +1,10 @@
+'use strict';
+var $ = require('../internals/export');
+var lastIndexOf = require('../internals/array-last-index-of');
+
+// `Array.prototype.lastIndexOf` method
+// https://tc39.es/ecma262/#sec-array.prototype.lastindexof
+// eslint-disable-next-line es/no-array-prototype-lastindexof -- required for testing
+$({ target: 'Array', proto: true, forced: lastIndexOf !== [].lastIndexOf }, {
+  lastIndexOf: lastIndexOf
+});