tests: MockBase() should load real repos, too.
drpm: add config options + docs, load updateinfo.xml
drpm: download delta packages if possible
tests: test rpm and drpm downloads from repo with deltas
get_package_target(): support the "donecb" callback
drpm: spawn delta rebuild jobs, report failures
drpm: fall back to rpm download on drpm errors
tests: test drpm to rpm failover
Hide the progress bar on failfast abort
Revert "doc: api: dnf.cli. Commands and resgistering them."

This reverts commit 04798f0e72a592b09c5accba23ee286371ef5302.