ostree admin deploy: Refactor bringing cleaning into `main`
ostree admin deploy: Refactor bringing cleaning into `main`

In the next commit I will add --no-prune which will affect cleaning.  By
doing this refactor we avoid having to add a NO_PRUNE flag.

Closes: #1418
Approved by: cgwalters

GNOME/ostree,GNOME/ostree,GNOME/ostree,GNOME/ostree,GNOME/ostree