Improve the error message

[max-moser]

Right now, when the draft is saved, the error message says:

Record saved with validation errors:

    Unknown field: Missing curation request. Please create a curation request, if the record is ready to be published.

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From my understanding this is done because the deposit form only shows certain hard-coded error types.
However, the curations aren't actually implemented via (custom) fields.
The error message itself is fine, but it would be nicer if the "Unknown field" weren't there.

[rekt-hard]

Your assumption about certain error types is correct.
This was part of a first implementation with a separate UI box for curations. It was implemented this way, to make sure a user understands that a curation request is required before being able to publish. Since we now have a tight integration with the deposit box, the publish button will not be visible until after the curation request has been accepted.

In general: Maybe we can first tackle the question, if this should be reported as a validation error. Per se, the record does not know about a request. Updating a record should maybe only report validation errors on the record itself.
Also with the tight UI integration, the whole validation error might not be relevant anymore.