Fixed typo in docs/ref/request-response.txt
Fixed #23618 -- Allowed apps with no models to still have migrations

Basically a4737bf6ae reapplied.
Updated gis_migrations tests
Fixed #23652 -- Restored database name after destroying test database

Thanks Bjarkias for the report.
Removed unused import
Fixed versionchanged indentation in topics/testing/advanced.txt.
Replaced dead links to python-distribute.org.