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/get-built-in.js

@@ -0,0 +1,11 @@
+'use strict';
+var globalThis = require('../internals/global-this');
+var isCallable = require('../internals/is-callable');
+
+var aFunction = function (argument) {
+  return isCallable(argument) ? argument : undefined;
+};
+
+module.exports = function (namespace, method) {
+  return arguments.length < 2 ? aFunction(globalThis[namespace]) : globalThis[namespace] && globalThis[namespace][method];
+};