Use a different hosting service for map tiles

[willf]

We might want to investigate the use of a third-party hosting service for map tiles in case the current provider stops hosting them, although as long as it continues to work, it makes sense to use them (and the Cloudflare cache).

[ericnost]

Mapbox https://www.mapbox.com/pricing#tilesets and ArcGIS Online https://doc.arcgis.com/en/arcgis-online/manage-data/publish-vector-tiles.htm may be options though I've actually never used either for this purpose.

[titaniumbones]

there are actually two pieces to this, I believe:

• base tile server. The version we are currently serving uses openstreetmaps tiles, whereas the old version used mapbox tiles (with an API key). It would be pretty straightforward to revert back to the mapbox method -- we'd just have to use the production build pipeline and provide a key. This might be necessary if the proejct is successful and starts to see heavy usage.
• CEJST custom tile server. Currently we just use the department of the interior CDN. We could either copy those directories to our own AWS (or other) location, or alternatively I think both @willf and I have successfully built all the assets using the existing data pipeline. so we could copy the relevant folder (which is just a couple of gigs) to that new location instead. In either case, I think there's an env variable for the base URL for all assets.