Failed `oc-mirror` mirroring should resume from last point where it left off

The proposed title of this feature request is:

"If for any reason OC mirroring fails to the local hard disk in a fully disconnected cluster, oc-mirror should be able to pick back up from where it left off second time when we run it again."

What is the nature and description of the request?
The request involves an improvement in oc-mirror.

Why does the customer need this?
Many customers are running oc-mirror in a slow internet environment due to security reasons. If customers are trying to mirror the whole registry like registry.redhat.io/redhat-operator-index:4.12, it may take a few days to do so. If, by any chance, it fails, it will not resume from where it ended.

List any affected packages or components:
Affected package/component: 'oc-mirror' binary.