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-to-reversed.js

@@ -0,0 +1,12 @@
+'use strict';
+var lengthOfArrayLike = require('../internals/length-of-array-like');
+
+// https://tc39.es/ecma262/#sec-array.prototype.toreversed
+// https://tc39.es/ecma262/#sec-%typedarray%.prototype.toreversed
+module.exports = function (O, C) {
+  var len = lengthOfArrayLike(O);
+  var A = new C(len);
+  var k = 0;
+  for (; k < len; k++) A[k] = O[len - k - 1];
+  return A;
+};