Revamped Crossfade support (#2087)

Revamped Crossfade support (#2087)

* Completely refactor crossfade support

Handle crossfade entirely in the streams controller, even if a player natively supports crossfading.

Support crossfading without flow mode if a player supports gapless.

Optionally support crossfade between different sample rate (only if player supports that).

Do not crossfade tracks of same album.

Unify the crossfade settings.

All players can now set the crossfade duration

Allow crossfade duration up to 15s

* Chore: Ensure sonos queue gets refreshed when items update