Coa entry form: add tick box for primary description act

Users have to be able to select a description act that is set as primary. Only this description should (in general) be displayed in search results.

• Check if Knowledge Pattern exists
• add tick box to coa entry form
• add search facet to filter between all blazons or only primary blazons
• Important: Only one description act can be the primary description act -> all other primary description acts for this dhor:CoatOfArmsRepresentation must be deleted
• Create issue that allows to allow setting the primary description act only with certain roles