Add EU 🇪🇺

[RVA2869]

A first push for the EU. Still much to do

[Abbe98]

Related discussions in #511 #508.

This is currently blocked by the geoshape requirement, I would however, for the time being suggest that we make it optional.

[RVA2869]

This is currently blocked by the geoshape requirement.

Wouldn't it be an option to use a world map SVG instead of geoshape + leaflet?

Something like: Commons

[Ainali]

It could possibly be a workaround. That would require to edit in the color and the link in the SVG file when adding a country rather than having the map be automatic. I think we are also limited to the shapes defined in the map, but perhaps it may be good enough for us. I think the biggest problem is that it would be difficult to click on a small country when the zoom is not there.