Support for Koito

**Is your feature request related to a problem? Please describe.**
Koito https://koito.io/ is a listenbrainz-compatible, self hosted scrobbler. It would be great to be able to use it instead of listenbrainz

**Describe the solution you'd like**
Since Koito is already listenbrainz compatible, just being able to change the base URL in listenbrainz should suffice
