Fix Northern Territory local gov data

[nf-s]

City of Darwin and City of Palmerston have ArcGis Hubs

• https://city-of-palmerston-open-data-cityofpalmerston.hub.arcgis.com/search?collection=Dataset
• https://open-darwin.opendata.arcgis.com/search?collection=Dataset

We currently don't have ArcGis Hub support in TerriaJS

• https://github.com/TerriaJS/product/issues/173

There are ArcGis server endpoints behind it - but they aren't very nice to browse

City of Darwin

• https://services6.arcgis.com/tVfesLETUHNU9Vna/ArcGIS/rest/services
• https://nationalmap.gov.au/#share=s-omgliG1TNYSvfiOkwiCZUmpY4AZ

City of Palmerston

• https://services-ap1.arcgis.com/PjwIgmNDvkMlgeWY/arcgis/rest/services/
• https://nationalmap.gov.au/#share=s-nLvWVdc8d21mM6mi6YnMi3ZPleP