Remove country code from internal dataset export
Remove country code from internal dataset export

It needs to be able to go back into the importer, and the importer
doesn't yet support that kind of format.

owid/owid-grapher,OurWorldInData/owid-grapher,OurWorldInData/owid-grapher,aaldaber/owid-grapher,aaldaber/owid-grapher,OurWorldInData/our-world-in-data-grapher,OurWorldInData/our-world-in-data-grapher,aaldaber/owid-grapher,OurWorldInData/owid-grapher,owid/owid-grapher,owid/owid-grapher,aaldaber/owid-grapher,OurWorldInData/our-world-in-data-grapher,OurWorldInData/owid-grapher,aaldaber/owid-grapher,OurWorldInData/owid-grapher,owid/owid-grapher,OurWorldInData/our-world-in-data-grapher,owid/owid-grapher