No admin interface for Bib Sources

There is no administration UI for managing bib sources. Since there's no system reason why the list of bib sources should be restricted to stock data, such an interface should be created.

An auto-generated admin interface would cover most of what's needed, although since there's a foreign key relationship between config.bib_source and vandelay.queued_bib_record that does _not_ set null on delete, either deleting a bib source will require special handling or the FK relationship action should be changed to "on update cascade on delete set null".

Evergreen 3.9+