[bug] fix hasAvailability

[qjhart]

The current hasAvailability only propoagates the experts' hasAvailability urls to the document. setup. I propose that we more accurately represent this with the preferred label as well, so...

{
  "_id": "expert/LDdgBTXN",
  "_version": 74,
  "_source": {
    "@id": "expert/LDdgBTXN",
    "@context": "http://localhost/api/schema/1/context.jsonld",
    "@graph": [],
   "hasAvailability": [{
          "skos:prefLabel": "Collaborative projects",
          "availabilityOf": "expert/LDdgBTXN",
          "@type": "Concept",
          "@id": "ark:/87287/d7mh2m/keyword/c-ucd-avail/Collaborative%20projects",
          "skos:inScheme": {
            "@id": "ark:/87287/d7mh2m/keyword/c-ucd-avail/"
          }
        }],
        "orcidId": "0000-0001-9829-8914",
        "@id": "expert/LDdgBTXN"
        }

This is more standard with our practice of just promoting @graph components to the document level.
Furthermore, we base the hasAvailability index in elastic search on the prefLabel so that filters will look like

/search?q=hart&hasAvailability=Collaborative%20projects

And finnally our schema will promote skos:prefLabel to prefLabel

[qjhart]

@UcDust does this seem reasonable? UI effects should be limited to your search formulation only, AFAIK.

[UcDust]

@qjhart yea this seems like it would work.