Add log translation hints for cinder

Current oslo libraries support translating log messages using different
translation domains and oslo would like to see hints in all of our code
by the end of juno. So cinder should handle the changes out over the
release.

Relate info about log translation hints as follows:
    https://blueprints.launchpad.net/oslo/+spec/log-messages-translation-domain-rollout
        https://review.openstack.org/#/c/70455

blueprint log-translation-hints
Change-Id: Ie9e4b7d5ef1a0a9727f35b1b31c147c1d47cbfab
Merge "Add log translation hints for cinder"