This is a bit more work than other queries, as it also breaks apart the
fetching of the job and the worker into separate ones. In other words,
internally the persistence layer API changes.
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.
