storage_service: Refuse to decommission if not in state NORMAL
storage_service: Refuse to decommission if not in state NORMAL

Backport: CASSANDRA-8741

5bc56c3 refuse to decomission if not in state NORMAL

avikivity/scylla,avikivity/scylla,duarten/scylla,avikivity/scylla,scylladb/scylla,raphaelsc/scylla,raphaelsc/scylla,duarten/scylla,kjniemi/scylla,kjniemi/scylla,duarten/scylla,raphaelsc/scylla,scylladb/scylla,scylladb/scylla,scylladb/scylla,kjniemi/scylla