Fetch mapit boundary data on search page

Assigns an `@authorities` hash to the view with `DIS` and `CTY` boundaries - or a `UTA` boundary in the case of a Unitary authority (e.g. Southampton - `SO14 OAB`).

Includes an `NPA` boundary if also covered by the South Downs or New Forest National Parks Authorities (e.g. `SO21 1PL`, `SO42 7QH`)

Passes the original query through to the search results page as an address or a postcode param
Having another look to see whether I've missed something obvious. The data I'm getting back - which may be a sign that my call to the endpoint's not quite right? - is in the format:

    {
        "144313": {
            "parent_area": null,
            "generation_high": 21,
            "all_names": {},
            "id": 144313,
            "codes": {},
            "name": "New Forest National Park Authority",
            "country": "E",
            "type_name": "National Park Authority",
            "generation_low": 21,
            "country_name": "England",
            "type": "NPA"
        },
        "2227": {
            "parent_area": null,
            "generation_high": 21,
            "all_names": {},
            "id": 2227,
            "codes": {
                "ons": "24",
                "gss": "E10000014",
                "unit_id": "17765"
            },
       }
      
        ...
        
        "debug_db_queries": [
            {
                "time": "0.003",
                "sql": ...
            }
        }
    }