This makes it easier to later also create `query_workesr.sql`,
`query_meta.sql` etc. so that the sqlc-generated code can follow the
same subdivision as the persistence service code itself.
No functional changes.
GORM has certain downsides:
- Code-first approach, where queries have to be translated to the Go code
required to execute them.
- GORM comes with its own SQLite implementation, which doesn't provide an
on-connect callback. This means that new connections cannot correctly
enable foreign key constraints, causing database consistency issues.
[SQLC](https://sqlc.dev/) solves these issues for us.
This commit doesn't fully replace GORM with SQLC, but introduces it for
a few queries. Once all queries have been converted, GORM can be removed
completely.
