MPRIS only updated on track change

[danirabbit]

What Happened?

If track metadata changes (such as loading album art), MPRIS isn't updated with the new data

Steps to Reproduce

1. Open Music and add some tracks
2. Without changing track, open MPRIS
3. See that track metadata in the app is complete while in MPRIS you may be missing artist or have file URI instead of track name

Expected Behavior

We should update MPRIS metadata when it changes in the audio object. Perhaps the metadata discoverer should fire a signal since metadata has to all be updated at once in MPRIS?

OS Version

8.x (Circe)

Session Type

Secure Session (Wayland)

Software Version

Latest release (I have run all updates)

Log Output

Hardware Info

No response