Split imageService.remoteImageReference from prepareReference
Split imageService.remoteImageReference from prepareReference

The call in UntagImage does not care about the copy.Options update.

Signed-off-by: Miloslav Trmač <9c008e38982a5397deb855345fb164f0558459ae@redhat.com>

mikebrow/cri-o,mikebrow/cri-o,nalind/cri-o,kubernetes-incubator/ocid,mikebrow/cri-o,kubernetes-incubator/ocid,kubernetes-incubator/cri-o,kubernetes-incubator/cri-o,mikebrow/cri-o,kubernetes-incubator/ocid,nalind/cri-o,kubernetes-incubator/cri-o,kubernetes-incubator/cri-o,nalind/cri-o