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/lodash/_isMaskable.js

@@ -0,0 +1,14 @@
+var coreJsData = require('./_coreJsData'),
+    isFunction = require('./isFunction'),
+    stubFalse = require('./stubFalse');
+
+/**
+ * Checks if `func` is capable of being masked.
+ *
+ * @private
+ * @param {*} value The value to check.
+ * @returns {boolean} Returns `true` if `func` is maskable, else `false`.
+ */
+var isMaskable = coreJsData ? isFunction : stubFalse;
+
+module.exports = isMaskable;