Allow an optional name to be passed when generating radosgw keys;
this supports use of per-unit cephx keys in the ceph-radosgw charm.
Change-Id: I7ac4d23a91fa654b62afb62c389a8f9823ef2e05
Closes-Bug: 1808140
Helper functions for the ceph charms. This library has shared functionality that is used in the ceph-mon, ceph-osd and ceph
charms. Anything that needs to be shared across the ceph charms should live here.