As discussed here it would be a good idea to implement a setting where end user can select a custom character that will be used to split multiple artist into separate values.

Current Behavior

A song has Contributing Artist value Artist1, Artist2. Navidrome reads the artist as a single value with name "Artist1, Artist2"

Expected Behavior

A song has Contributing Artist value Artist1, Artist2. Navidrome reads the artist and recognizes there are two or multiple artists separated by comma and song show up under the Artist page of Artist1 and Artist2.
The separator character can be selected (comma in the above example) by end user depending on how their library is tagged.