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-length.js

@@ -0,0 +1,11 @@
+'use strict';
+var toIntegerOrInfinity = require('../internals/to-integer-or-infinity');
+
+var min = Math.min;
+
+// `ToLength` abstract operation
+// https://tc39.es/ecma262/#sec-tolength
+module.exports = function (argument) {
+  var len = toIntegerOrInfinity(argument);
+  return len > 0 ? min(len, 0x1FFFFFFFFFFFFF) : 0; // 2 ** 53 - 1 == 9007199254740991
+};