rpm-ostree/cli_status: support local OCI deployments

Add support for local OCI deployements, no longer erroring out.

Use the `ostree-ext` crate to parse the ostree image reference properly.
This will allow zincati to query the OCI graph and rebase to OCI images
for updates.

Also change the base-commit-meta object to support the OCI case where
this is actually an escaped serialized OCI manifest.
Use the `oci-spec` crate to deserialize it and extract the core os
stream info from the base OCI annotations.
This works around coreos/rpm-ostree#5196