cubicweb-saem_ref #15625606 add oaipmh metadata prefix to export profil as rng/xsd + version [validation pending]

prioritynormal
typeenhancement
done in0.13.0
load left0.000
closed by#ef44cecf32de Add OAI metadata prefix to expose different versions and formats of SEDA profile.
patchAdd OAI metadata prefix to expose different versions and formats of SEDA profile. [applied]