Add data service endpoint to API corresponding to DCAT

[samueljackson92]

See here:

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

We could have an endpoint https://mastapp.site/json/service

An example of that this endpoint might return:

{
  "@context": "https://www.w3.org/ns/dcat#",
  "@type": "dcat:DataService",
  "@id": "http://example.com/data-service",
  "dct:title": "Example Data Service",
  "dct:description": "A data service providing real-time access to environmental data.",
  "dct:identifier": "env-data-service-001",
  "dct:publisher": {
    "@type": "foaf:Organization",
    "foaf:name": "Environmental Data Agency",
    "foaf:homepage": "http://example.com/agency"
  },
  "dct:contactPoint": {
    "@type": "vcard:Contact",
    "vcard:fn": "Support Team",
    "vcard:hasEmail": "mailto:[email protected]"
  },
  "dcat:endpointURL": "http://example.com/api/v1",
  "dcat:servesDataset": [
    {
      "@id": "http://example.com/dataset/air-quality"
    },
    {
      "@id": "http://example.com/dataset/water-quality"
    }
  ],
  "dcat:endpointDescription": "http://example.com/api-docs",
  "dct:license": "http://example.com/license",
  "dct:spatial": {
    "@type": "dct:Location",
    "dct:location": {
      "@type": "dct:Location",
      "rdfs:label": "Global"
    }
  },
  "dct:temporal": {
    "@type": "dct:PeriodOfTime",
    "schema:startDate": "2020-01-01",
    "schema:endDate": "2024-12-31"
  },
  "dct:theme": [
    "http://example.com/themes/environment",
    "http://example.com/themes/data-access"
  ]
}