improvement(cluster.py): Supporting update_db_packages that are supplied as tar.gz
improvement(cluster.py): Supporting update_db_packages that are supplied as tar.gz

In case the update_db_packages url contains rpms that are tar.gz,
this command will untar them before trying to install them.

scylladb/scylla-longevity-tests,scylladb/scylla-longevity-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-cluster-tests,scylladb/scylla-longevity-tests,scylladb/scylla-cluster-tests