Artists with no album shouldn't be listed in Artists page
Steps to reproduce
Import album associated to Various Artists and with tracks associated to specific artist.
What happens?
In the Artists page you can see some artists with 0 album and empty cards. It is confusing and looks awkward:
What is expected?
Those artists should not be displayed or displayed in a different way.
Context
Funkwhale version(s) affected: 0.19.1
All songs were uploaded/imported on previous releases of Funkwhale.