image improvements

[AEnterprise]

noticed when upgrading koel that it needs to redownload a bunch of images, because they are stored in the container itself. This also bloats it quite a bit. The docker compose files already had a partial solution for it so i expanded it with a proper /cache folder. This also gives koel a central place for future expansions.

I considered moving the search index into it as well, people already have that mapped or data in the volume, and while koel can easily recover and re-download images, the search index going poof really breaks the application and needs manual intervention to rebuild

while updating that i also noticed it was doing 2 apt updates so merged them together