Some Media-Controls(mpris) refactors

This PR refactor the Media-Controls(mpris) to be in a better shape and more responsive, which includes:

set volume on volume events (instead of on every tick)
set progress to actual new progress (instead of using the old / stale progress)
dont start mpris if not wanted (and restart / stop on config change)
move reloading config logic to a separate function
general refactors to have some separate functions for mpris things (change volume, handle events, update progress)

tramhao / termusic