[Suggestion] Also allow per-applet music

[ErdbeerbaerLP]

This project now supports adding home menu music in some way.
However, I would really like to add music to the eShop applet instead. (Another place where music is really missing).
Sadly it does not detect applets running (yet).
It would be a very nice feature to allow selecting playback status on a per-applet basis, too.
Maybe even allow configuring a specific mp3 file to play for applet XY while still allowing to change music for games / home menu without impacting the applet one.
Time to improve the switch console even more at places nintendo does not :)
Still very thankful for the home menu music feature