Suggestion: enable metadata fields to require uniqueness

[poikilotherm]

Overview of the Suggestion
We would like Dataverse software to check for uniqueness of metadata fields.

What kind of user is the suggestion intended for?
API User, Curator, Depositor

What inspired this idea?
We had a few datasets where folks reused the same ORCiD für multiple authors by accident.

What existing behavior do you want changed?
As this is something that needs to be checked on the server side, it seems like an extension of the metadata schema spec is necessary in addition to a specialized validator.

Any brand new behavior do you want to add to Dataverse?
It's not really brand new, as we already do validations on fields. The new behaviour is enabling cross-field checks. For now this is only about uniqueness, but there are probably more options.

Any open or closed issues related to this suggestion?
I couldn't find anything, but that might just be me looking for the wrong keywords during the search.

Are you thinking about creating a pull request for this issue?
Yes, we will put this on our agenda for now. But obviously we'd like to hear what others have to say first.

[pdurbin]

Makes sense. When looking at #11118 @sekmiller and I chatted a bit about how there is no validation for ORCIDs. Dataverse wants you to enter just the unique identifier and provides a link to your ORCID. If you enter the full ORCID URL as the identifier, Dataverse will not complain but doesn't make it linkable. In b9d0146 I added a note to the guides about how to enter ORCIDs.