rados: replace copy-n-paste *_command functions argument handling
rados: replace copy-n-paste *_command functions argument handling

Replace the argument handling (wrangling?) around *_command functions,
such as MonCommand, with the new command input and output helper types
from the internal/cutil package.
No external change should be visible.

Signed-off-by: John Mulligan <eda8ad33169deab44f9fe65847f99e368da6c91b@redhat.com>

ceph/go-ceph,ceph/go-ceph,ceph/go-ceph