Investigate integrating with DuckDB/Object storage vs. postgres requirement

@theferrit32 is putting together code that will allow seqrepo to use DuckDB over blob storage as opposed to postgres. Similar could be done for UTA. This will ease adoption and lower the administrative costs of maintaining seqrepo/UTA reference sequences.

Will try to get this merged into seqrepo, alternatively can branch or build on top of it to implement this.