As had been noted on some of the commands, 'ingest' was not the best place for
them. However, [project-level apps are not supported in
Django](https://forum.djangoproject.com/t/allow-project-to-have-management-commands/5220/2)
So just create a 'main' app. I want to qualify it as 'myproject-main' though, to avoid
further unqualified global namespace pollution. And I want to avoid prefixing with 'bugsink'
b/c that's annoying for tab-completion. So 'bs' it is.
I've moved all commands over; even though a case could be made that the "feeding" commands
(raise_exception, send_json, stress_test) are somewhat related to ingestion, that's not
a very good case :-)
why: simply motivated by Python's own EOL-cycle; i.e. I'm not
actively going to use any 3.13 or 3.9 features now.
how: updating test-matrixes; but no actual local testing done yet
