Add loader to get locations from Vaccinate the States

[Mr0grog]

We should add a loader that gets locations and external IDs (“concordances” in Vaccinate the States’s terminology) from Vaccinate the States. See documentation here: https://docs.vaccinatethestates.com/docs

Their location entries are GEOJSON and look like:

{
  "type": "Feature",
  "id": "recJlvDofc96TF0Eh",
  "properties": {
    "name": "CVS Pharmacy, Inc. #09665",
    "state": "CA",
    "location_type": "Pharmacy",
    "phone_number": "(323) 478-8310",
    "full_address": "5944 N Figueroa St, Los Angeles, CA 90042",
    "city": null,
    "county": "Los Angeles",
    "zip_code": null,
    "hours": {
      "unstructured": "Monday: 08:00AM-09:00PM\nTuesday: 08:00AM-09:00PM\nWednesday: 08:00AM-09:00PM\nThursday: 08:00AM-09:00PM\nFriday: 08:00AM-09:00PM\nSaturday: 09:00AM-06:00PM\nSunday: 10:00AM-06:00PM"
    },
    "website": "https://www.cvs.com/store-locator/details-directions/009665",
    "vaccines_offered": [
      "Pfizer"
    ],
    "concordances": [
      "cvs:09665",
      "vaccinefinder:a91612d0-bf7a-4ffc-a1e7-f595407b209c"
    ],
    "last_verified_by_vts": "2021-05-12T00:25:42.567429+00:00",
    "vts_url": "https://www.vaccinatethestates.com/?lng=-118.18915&lat=34.11106#recJlvDofc96TF0Eh"
  },
  "geometry": {
    "type": "Point",
    "coordinates": [
      -118.18915,
      34.11106
    ]
  }
}

[Mr0grog]

This should also help with vaccines.gov, since VtS’s concordances include vaccines.gov/vaccinefinder.org IDs.

[Mr0grog]

@astonm covered a huge chunk of this in #304, and I’m not sure further work on this is particularly worthwhile now. Closing.