Remove dependency to S3 files

Currently, running raster analysis locally requires to have a boundary file on S3. We should remove this dependency. To do so, we have two options.

1. When running locally, we send the geojson boundaries instead of url

2. Instead of using S3, we add a “defaultUrl” to each country, pointing to their main deployment URL. This way, we don’t need to maintain files on S3 and the URL will be something like prism-mongolia.org/data/boundary_file.json

Since the API already accepts zones as a GeoJSON, it is probably the easiest option.