ceph-volume: batch - major refactor

ceph-volume: batch - major refactor

This completely refactors the batch code in order to make use of the
create/prepare code path for creating OSDs instead of having a second
code path doing this. This not only eases the maintenance burden but
also adds various features and fixes bugs. This subcommand can now
handle LVs, replace OSDs, reuse VGs and has a better notion of
idempotency.

Signed-off-by: Jan Fajerski <jfajerski@suse.com>