[Request] Loader displays notifications for delisted plugins

[TrainDoctor]

Please confirm

• I have searched existing issues
• This issue is not a duplicate of an existing one
• This is not a request for a plugin

Feature Request Description

Plugins that are marked as not visible aka delisted from the production store should send a notification back to all Decky users that notifies them that a plugin has been delisted.

Further Description

This could work by the loader client filtering the plugins the user is notified of being delisted down to ones that the user has installed or far more simply as just a generic notification that a plugin has been delisted. Preferably grouping multiple delistings into a single notification.