cubicweb-saem_ref #15626236 use canonical uri in rdf export [validation pending]

eg <site>/<eid>, not <site>/<type>/<name>

prioritynormal
typebug
done in0.13.0
load left0.000
closed by#e2dc7fe34f15 [rdf] Use ark based url in RDF export, rather than 'absolute_url()'
patch[rdf] Use ark based url in RDF export, rather than 'absolute_url()' [applied]