tests: Replace STI tests with upstream FMF tests
Upstream now includes FMF metadata and the setup/run scripts to run the
nondestructive verify tests in a provided testbed. These are now
constantly being verified through packit.
Drop the code duplication and just add some minimal FMF metadata to
discover the tests.
This currently has to hardcode the version number. This eventually must
become more flexible in FMF (https://github.com/psss/tmt/issues/585),
but until then we can update this in the cockpituous release scripts.