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/_castFunction.js

@@ -0,0 +1,14 @@
+var identity = require('./identity');
+
+/**
+ * Casts `value` to `identity` if it's not a function.
+ *
+ * @private
+ * @param {*} value The value to inspect.
+ * @returns {Function} Returns cast function.
+ */
+function castFunction(value) {
+  return typeof value == 'function' ? value : identity;
+}
+
+module.exports = castFunction;