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-positive-integer.js

@@ -0,0 +1,10 @@
+'use strict';
+var toIntegerOrInfinity = require('../internals/to-integer-or-infinity');
+
+var $RangeError = RangeError;
+
+module.exports = function (it) {
+  var result = toIntegerOrInfinity(it);
+  if (result < 0) throw new $RangeError("The argument can't be less than 0");
+  return result;
+};