Add number of tracks and discs of an album to API

/label Type: New feature Status: Need triage

What is the problem you are facing?

While working on improving the mopidy plugin for funkwhale, I noticed that there is currently no way to determine the amount of tracks and discs for an album from the API, which makes multi-CD albums a problem when browsing the library using ncmpcpp.

What are the possible drawbacks or issues with the requested changes?

Currently, this is how the playlist looks like when mopidy has wrong information about album track amount:

The /0 are because as for now, the num_tracks for an album are determined by this snippet of code:

len(payload.get("tracks", [])),

I guess before the track endpoint got added into the API, the tracks were returned as a list with the album, which made the code above work.

Context

Other streaming services API have meta about album track and disc amount in their responses, so why not in Funkwhale?