Make "bin/storage destroy" target individual hosts in database cluster mode

Summary:
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