feat(oai): add seda2.1rng export in oai
This allows the metadataPrefix seda2.1rng
in oai such as :
/oai?metadataPrefix=seda2.1rng&verb=ListRecords
This uses the profile_generation defined here, that may need adaptations (see seda#15 (closed)).
This MR needs the cube seda with seda2.1 : seda!12 (closed)
linked to seda#22 (closed)
Edited by Noé Gaumont