How to require that each primitive contains contact information and bug tracker link?

Unless we can assume that all TA1 performers watch issues on the primitive repo, issues need to be reported on their upstream repo.

Right now, we seem to be looking at the 'package_uri', and go report issues there if it is a GitHub or GitLab URL. Adding an actual URL to a bug tracker there that the primitive author watches might be a good idea.

This field should be made optional at first for compatibility. We could even fill it in ourselves from the 'package_uri'.

Edit (by @mitar): Renamed title. There is already metadata for this under source.uris and source.contact but people do not provide this.