This fixes sorting tracks by album & artist, and should allow for a
better & more consistent sort, especially if we add more criteria or
more listing functions

Bypass those tables and directly propagate the presence state in the
media

It is already stored that way

The filename stored in the media is only a shortcut when it comes to
sort things, so it's fine to use it in a case insensitive way, as
opposed to the mrl stored in the File table

This will help fix COUNT request results

This can be used to avoid full table scans when knowing if a media is
present in a playlist or not

So that we can use it for vacuuming old external media

This is now up to the user to chose how many items they chose to fetch
from the history, through the returned Query's item() method

It's now using the regular Media table & requests

This will ease up the migrations, as those are the only tables we
absolutely need to keep the content of. It will be easier to just create
a new version of the model, and include it from the migration script,
instead of having the main "create table" and the migration one

We now return all media as a single query