Upgrade to coil 2.0.0 and completely refactor the usage of coil to work
with the new library structure. This also fixes the issue where error
icons will just re-appear due to blocking calls. I had to add a fix on
my end and also use the new caching system in coil 2.0.0.
Finally add tab customization. This implementation is a
bit ugly, but I had to futureproof it for playlists and I'm
planning to clean up a lot of the duplicate code across the app.
This addition notably allows a default tab to be set, which is
something that was widely requested in #12. This UI rework finally
allows it to be added.