Edit "Entailment label" of a copied problem

In principle, it should be possible to change the entailment label of a copied problem:
https://langpro-annotator.hum.uu.nl/annotate/580340
When copied, it defaults to Unknown, but often one needs to set it to a correct entailment label

Start by reproducing the copied-problem flow at the linked annotation page and trace where the copied entailment label is displayed and changed. The work is done when a copied problem no longer forces Unknown and a user can select and retain the intended entailment label.

Written by the indexing model from the issue text.