expose silent arg in get_geodata

[tgrandje]

This exposes the silent arg in get_geodata (it was only accessible in the inner _get_geodata function) and pass it to the private function.

Also fix snake case for crs_polygon.

[tfardet]

for some reason I cannot seem to rerun the tests... I wanted to check what went wrong... @tgrandje can you do it?

[tgrandje]

nope, not available to me either. I'll try to make a dummy commit but I'm afraid if we have a failure due to localdata (as I think we have), we're not gonna fix the tests here either.

[tgrandje]

@tfardet that one's good to go