cubicweb-datacat #8303410 use a controller vocabulary to describe agent type [validation pending]

As per https://joinup.ec.europa.eu/catalogue/distribution/dcat-ap_final_v101pdf, ADMS publisher type vocabulary can be used to control dct:type property of Agent entity.

prioritynormal
typeenhancement
done in0.5.0
load1.000
load left0.000
closed by#c65b3b8dd3db Replace Agent's `dcat_type` attribute by a publisher_type relation to a Concept
patchReplace Agent's `dcat_type` attribute by a publisher_type relation to a Concept [applied][migration] Import ADMS vocabularies [applied]