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/require-object-coercible.js

@@ -0,0 +1,11 @@
+'use strict';
+var isNullOrUndefined = require('../internals/is-null-or-undefined');
+
+var $TypeError = TypeError;
+
+// `RequireObjectCoercible` abstract operation
+// https://tc39.es/ecma262/#sec-requireobjectcoercible
+module.exports = function (it) {
+  if (isNullOrUndefined(it)) throw new $TypeError("Can't call method on " + it);
+  return it;
+};