Method to right invalid manifests

As an administrator of a NXRM docker respoitory with invalid assets, I would like a non-manual way to clean them to continue to save disk space and to avoid WARNs in my logs on execution of the "Purge unused docker manifests and images" cleanup task.

Background

In NEXUS-12962, the solution to the ticket prevented the scheduled task from erroring as well as stopping the cleanup process however it still leaves invalid assets around as it could not be determined if they could be cleaned up. If this number grows, it becomes increasingly frustrating to clean these out manually and for each one that is present a WARN fires in the nexus.log currently, so if there were (example) 20000, you'd have 20000 WARNs.

Hopefully there's a clean way to identify these "invalid" assets are valid or to perform a cleanup. This is a ticket to track that potential as well as guage public interest.