Try to always decode RPM data instead of working with bytes
Since Fedora 31, those are unicode strings, but before they are bytes
There is dummy .decode() method provided for backwards compatibility,
but everything else stopped working. By always decoding first,
we try to minimize the problem.
In the future (when RPM is updated everywhere), the decode calls
shall be removed.
See https://pagure.io/FedoraReview/issue/356
See https://bugzilla.redhat.com/show_bug.cgi?id=1693751