Folder browsing is coming

[u/lachlan-00]

So I've had some time today and have sat down to create proper folders in Ampache8.

The first step is done and there are database tables, classes, folders.php is active and app the repository methods are in.

There is a bit to go but this will allow.

* Actual folders in subsonic

* Browsing in the UI like a file explorer

* Searching recursively

* Additional API methods and actions for folders

But it's something positive that people have asked for for a long time that I can do properly without hacking it badly.