fix(manager): Added handling of empty manager cql/rest status
fix(manager): Added handling of empty manager cql/rest status

Due to recent changes in the manager,
the manager does not query nodes that are properly down (DN) for rest and cql status
and instead of the usual DOWN status prints '-' as the status.
I updated the code to parse the '-' status as DOWN

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