Add dcat:mediaType to Distribution in the DSP DCAT profile

[jmcanterafonseca-iota]

Rationale:

dcterms:format is being used by the DSP profile to convey aspects related to the transport delivery, such as HTTP pull or push, etc. It must be a URI as it has been tagged as @vocab in the LD Context.

I have noticed a mistake, also being done by myself, towards associating format with media types and that can be misleading.

The proposal is to leave format as it is and add to the profile dcat:mediaType so that Distributions can be properly declared with their distribution format and their Media type for instance:

{
   "@type": "Distribution",
   "format": "example:Http-Data-Pull",
   "mediaType": "application/ld+json"
}

[arnoweiss]

The media type (and other metadata like api typization, schema files) are tied closer to the Dataset itself. I've seen some of them that use a dataspace-specific additional property there.

[jmcanterafonseca-iota]

From my point of view the Dataset is independent of any manifestation ...

https://www.w3.org/TR/vocab-dcat-3/#introduction

Data described in a catalog can come in many formats, ranging from spreadsheets, through XML and RDF to various specialized formats. DCAT does not make any assumptions about these serialization formats of the datasets but it does distinguish between the abstract dataset and its different manifestations or distributions.

[ssteinbuss]

This requires further investigation. We consider this at the moment as a new feature request and schedule this for a future release. However, as we have implementations following our current approach, we would like to hear from other implementations on their experience before deciding on a way forward.