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/internals/is-array.js

@@ -0,0 +1,9 @@
+'use strict';
+var classof = require('../internals/classof-raw');
+
+// `IsArray` abstract operation
+// https://tc39.es/ecma262/#sec-isarray
+// eslint-disable-next-line es/no-array-isarray -- safe
+module.exports = Array.isArray || function isArray(argument) {
+  return classof(argument) === 'Array';
+};