There are a number of tests which require creating a repository on the
fly, and they each do it their own way. To reduce code duplication, lift
out this common pattern into a helper called `CreateDeclarativeRepo()`,
which lets us create a repository, set up enabled and disabled repo
units, and even add, delete, or update files.
Also convert a number of users of this pattern to the new helper - those
users that I introduced, and are in code introduced by Forgejo in the
first place.
Signed-off-by: Gergely Nagy <forgejo@gergo.csillger.hu>
342b7bae3c