IQSS/8690 Make producer optional

[qqmyers]

What this PR does / why we need it: This PR makes the change suggested in #8690 to not require the producerName so that the producer field becomes optional.

Which issue(s) this PR closes:

• Closes #8690

Special notes for your reviewer:

Suggestions on how to test this: Testing requires a fix for #11992 .Once that is available/merged, you should be able to check in the UI that it is now possible to uncheck the Producer field on a given Dataverse and verify that the field no longer shows for datasets created within it.

Does this PR introduce a user interface change? If mockups are available, please link/include them here:

Is there a release notes update needed for this change?:

Additional documentation: