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/to-uint8-clamped.js

@@ -0,0 +1,7 @@
+'use strict';
+var round = Math.round;
+
+module.exports = function (it) {
+  var value = round(it);
+  return value < 0 ? 0 : value > 0xFF ? 0xFF : value & 0xFF;
+};