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/promise-resolve.js

@@ -0,0 +1,13 @@
+'use strict';
+var anObject = require('../internals/an-object');
+var isObject = require('../internals/is-object');
+var newPromiseCapability = require('../internals/new-promise-capability');
+
+module.exports = function (C, x) {
+  anObject(C);
+  if (isObject(x) && x.constructor === C) return x;
+  var promiseCapability = newPromiseCapability.f(C);
+  var resolve = promiseCapability.resolve;
+  resolve(x);
+  return promiseCapability.promise;
+};