Always x-check country labels against Natural Earth

[nvkelso]

Every now and then a fake country pops up in OpenStreetMap (a problem). And every now and then new real countries pop up, though recognition by wider international audiences does lag (an opportunity).

Currently we do compare OSM countries with Natural Earth countries via transform.py#L8889-L8922.

For non-matching countries, I propose we additionally modify the kind value to unrecognized (in addition to limiting the min_zoom blast radius to say 8 instead of 6).

We should also update the note in https://github.com/tilezen/vector-datasource/blob/master/yaml/places.yaml#L146-L147

This would match more what we do for disputed boundaries that are default unrecognized:

• https://github.com/tilezen/vector-datasource/blob/6e057196694b7896862c8bc2786389ad5b083f0e/docs/layers.md#viewpoints-for-disputed-boundaries

[nvkelso]

Requires #2075

Related to #2076.

[nvkelso]

Fixed via #2068 and #2069.