Add PostgreSQL support as an alternative to SQLite in refactor

I mean honestly all that is really necessary would be Postgres. It runs great, it can scale very easily, it's very extensible and many things are built ontop of it. It supports standard SQL syntax and isn't some weird niche and many things are compatible with it or meant as a drop in replacement for it in extreme cases. Also compared to all the other options it is one of the few that can truly be ran cloudnative and scale without hassle and it is incredibly efficient even for small setups.