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.number.parse-int.js

@@ -0,0 +1,10 @@
+'use strict';
+var $ = require('../internals/export');
+var parseInt = require('../internals/number-parse-int');
+
+// `Number.parseInt` method
+// https://tc39.es/ecma262/#sec-number.parseint
+// eslint-disable-next-line es/no-number-parseint -- required for testing
+$({ target: 'Number', stat: true, forced: Number.parseInt !== parseInt }, {
+  parseInt: parseInt
+});