Make "bin/storage destroy" target individual hosts in database cluster mode
Ref T13336. Currently, "bin/storage destroy" destroys every master. This is wonderfully destructive, but if replication fails it's useful to be able to destroy only a replica.
Operate on a single host, and require "--host" to target the operation in cluster mode, so bin/storage destroy --host dbreplica001 is a useful operation.
Test Plan: Ran bin/storage destroy with various flags locally. Will destroy secure002 and refresh replication.
Maniphest Tasks: T13336
Differential Revision: https://secure.phabricator.com/D20784