Hide Notification "Unity Editor plugin installed" after protocol connection is established

1. Notification is shown
```Unity Editor plugin installed
Please switch to Unity Editor to load the plugin.
```

2. User switches to Unity
Plugin is loaded. Protocol connection is established.

And we can hide Notification when connection is established.

Start by locating the code that displays the "Unity Editor plugin installed" notification and the entry point where the protocol connection becomes established. Verify the notification is dismissed after that connection event, while preserving the existing plugin-loading behavior.

Written by the indexing model from the issue text.