db: do case-insensitive explicit sorting of RepoGroup names This does not change the implicit sorting enabled via __mapper_args__, which is a bad idea anyway (and now deprecated), and will have to be dealt with in a later changeset. The use of __mapper_args__ implicitly adds sorting to every query of RepoGroup objects throughout the code (including implicit queries via relationships). For the relationships, __mapper_args can be replaced with "order_by" on each individual relationship, and it's reasonably straight-forward to identify every RepoGroup query throughout the code, and add explicit sorting. But we don't really need that sorting most of the time, so a better way forward may be to identify all the places that actually needs the sorting, make it explicit there, and then kill the __mapper_args__. (Anyway, future work.)