[DEV] Add a separate RPM that contains all containers

For standard installation, pulling containers from ghcr on startup is fine.  For airgap, we'll need a separate RPM package that includes the containers.  `skopeo` has the ability to download layers and `podman save/load` can target an oci-directory for containers.  We should be able to automate the creation of a container RPM that includes the layer cache of all containers included in the release.