Process queries for HexGrid objects.
:param request: HTTP GET request
:return: JSON format of HexGrid (only pk and count) or GeoJSON of the geom of HexGrid.

GET /api/occurrence/grid/?type=occurrence&taxon=9764340
HTTP 200 OK
Allow: OPTIONS, GET
Content-Type: application/json
Vary: Accept

{
    "features": [],
    "crs": {
        "type": "name",
        "properties": {
            "name": "EPSG:3031"
        }
    },
    "type": "FeatureCollection"
}