Fix volume name support of unmanage and replication commands

Volume not found error occurs when running these commands via cinderclient
with volume name as an argument.
unmanage, replication-promote, replication-reenable

However in their help text, it is described that Name and ID are supported.
Therefore, this patch fixes volume name support to their argument.

Closes-bug: #1374211
Change-Id: I8b90523d8e79a65eb27ff4e99820e8cb3feb3120
Merge "Fix volume name support of unmanage and replication commands"