[RFE] Add support for mirroring CI/Nightly releases with oc-mirror tooling

The current release of oc-mirror only allows mirroring of releases that are available in the GA channels. Sometimes we need to mirror CI or Nightly releases from the CI registry.

It would be great to add support for mirroring such releases[1] from oc-mirror. 

Example: 

registry.ci.openshift.org/ocp/release:4.11.0-0.ci-2022-08-17-012222

 [1] https://openshift-release.apps.ci.l2s4.p1.openshiftapps.com/