cubicweb-datacat #6822224 Add themes for datasets [validation pending]

for theme:

  • relation between catalog and concept scheme
  • restrict dataset.theme choices according to scheme linked to its catalog
priorityimportant
typeenhancement
done in0.4.0
load left0.000
closed by#a2ba4adc8577 [schema] Add relations to SKOS concepts and concept schemes
patch[schema] Add relations to SKOS concepts and concept schemes [applied]