Fixes 4740: Change base query to use inner joins

[jlsherrill]

I saw improvements with package queries by around 2x. Errata query times were very similar to before.

To test:

Load a bunch of repos and sync them (make repos-import && go run cmd/external-repos/main.go nightly-jobs). You might add some large fedora repos too.

in content-sources-backend go.mod add this under go 1.23:

replace github.com/content-services/tang => /home/jlsherri/git/tang

(replace with path to your checkout).

go get ./...

(Note that when switching branches, or modifying code in tang, you must rm release/content-sources before you make run to pick up the changes

• Confirm that listing rpms and advisories for templates works
• compare the counts before and after this change
• To see a time difference, you can enable query logging in postgres:

psql --host localhost -U pulp
ALTER SYSTEM SET log_min_duration_statement = 25;
select pg_reload_conf();

Now after fetching some set of content, you can run podman logs --tail 1000 cs_postgres_1 and see the time it takes:

LOG:  duration: 208.538 ms

You can switch back and forth between main and this branch to see the changes. You may want to compare the times (should be about half).

[rverdile]

also seeing ~2x speedup!