Define CIS JSON and CIS RDF media types and/or approach for negotiation by profile

[jerstlouis]

OGC needs to decide whether to adopt negotiation by profile in OGC API.
If we have negotiation by profile, we could use the base application/json and application/ld+json media types. Otherwise, we need dedicated media types for CIS JSON and CIS RDF.

See also opengeospatial/NamingAuthority#54
See also opengeospatial/ogcapi-common#8

[pebau]

negotiation per se is a fine extra, cream in the coffee, but simple things must remain simple. In this case: access to formats should be possible without having to think of negotiation. In particular, CIS JSON needs a unique identifier which can be used in the straightforward naive manner.