Add releasever_{major,minor} tests

[evan-goode]

Backports #1359 to dnf-4-stack.

Adds a test for the new --releasever-major and --releasever-minor options.

Requires rpm-software-management/dnf#2198 and rpm-software-management/libdnf#1689.

For https://issues.redhat.com/browse/RHEL-68034.

[kontura]

I think it would be good to also test that $releasever is not affected by setting major/minor.

Otherwise it looks good to me.

[kontura]

I was looking into it a bit more and I realized it would probably be good to have a test where the minor/major values are overridden by package provides since that is the intended use-case.
It also uses a different code path in both libdnf/dnf.

[evan-goode]

I think it would be good to also test that $releasever is not affected by setting major/minor.

I was looking into it a bit more and I realized it would probably be good to have a test where the minor/major values are overridden by package provides since that is the intended use-case.

Both done, good suggestions.