Finishing the deprecation of the skip_mode function in favor of pytest.mark.skip_mode. This PR is only cleaning and migrating leftover tests that are still used and old way of skip_mode. Closes scylladb/scylladb#28299
Extension of the cluster tests, where all tests require externally mounted volumes to be used by scylla cluster nodes. The volumes are passed with --workdir.
The volumes can be of any size. A help generator space_limited_servers is provided
to easily create a cluster of any given number of nodes, where each node operates in
a separate volume.