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/level-errors/errors.js

@@ -0,0 +1,16 @@
+var createError = require('errno').create
+var LevelUPError = createError('LevelUPError')
+var NotFoundError = createError('NotFoundError', LevelUPError)
+
+NotFoundError.prototype.notFound = true
+NotFoundError.prototype.status = 404
+
+module.exports = {
+  LevelUPError: LevelUPError,
+  InitializationError: createError('InitializationError', LevelUPError),
+  OpenError: createError('OpenError', LevelUPError),
+  ReadError: createError('ReadError', LevelUPError),
+  WriteError: createError('WriteError', LevelUPError),
+  NotFoundError: NotFoundError,
+  EncodingError: createError('EncodingError', LevelUPError)
+}