Improve handling of DUOS replicas

[nadove-ucsc]

Replicas containing the dataset description from DUOS should be given a distinct replica_type: "duos_dataset_registration". There should be a way to links the rows in this table to those in the anvil_dataset table. Perhaps having the same entity ID will be sufficient. We should also add the DUOS ID to these replicas.

[dsotirho-ucsc]

Assignee to consider next steps.

[hannes-ucsc]

It is very tempting to continue exploiting the Terra imported loop hole. I want to sit on this for a bit and see if the current behavior get in the way of some of the other outstanding verbatim manifest work.

[hannes-ucsc]

Move to backlog.