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/eslint/lib/rule-tester/index.js

@@ -0,0 +1,5 @@
+"use strict";
+
+module.exports = {
+    RuleTester: require("./rule-tester")
+};