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/document-create-element.js

@@ -0,0 +1,11 @@
+'use strict';
+var globalThis = require('../internals/global-this');
+var isObject = require('../internals/is-object');
+
+var document = globalThis.document;
+// typeof document.createElement is 'object' in old IE
+var EXISTS = isObject(document) && isObject(document.createElement);
+
+module.exports = function (it) {
+  return EXISTS ? document.createElement(it) : {};
+};