[Feature Request] - Add the option to download all tracks

[jamie6king]

Summary

Add an option in settings to download all tracks that are available.

Description

Add an option (probably with a warning) to download all the tracks on to the device in order to save data while out. Currently you can download specific songs / albums, but this can get annoying if you have a lot.

Maybe add a warning that this will use a lot of storage space?

Use Case

Allows full offline playback, which is rare for a Subsonic / Navidrome client.

Additional context