Add full precision GeoJSON version for TopoJSON only datastes

[jsanz]

Elastic Maps will always prefer TopoJSON as a convenient format with a good balance between data size and precision. Still, GeoJSON has a broader adoption in the industry, so we will provide a better service to our users if we offer our files in that format additionally.

The proposal then is for our current TopoJSON datasets (World Countries, Admin Regions, USA counties) to also be exposed in GeoJSON format in the EMS manifest. This format will be preferred by EMS Landing Page at <maps.elastic.co>.

This task is affected by elastic/kibana#71975 and related to elastic/ems-landing-page#255

[jsanz]

Fixed at #196