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/array-method-is-strict.js

@@ -0,0 +1,10 @@
+'use strict';
+var fails = require('../internals/fails');
+
+module.exports = function (METHOD_NAME, argument) {
+  var method = [][METHOD_NAME];
+  return !!method && fails(function () {
+    // eslint-disable-next-line no-useless-call -- required for testing
+    method.call(null, argument || function () { return 1; }, 1);
+  });
+};