Add country nationality

[mehranabi]

Hello, Hope u are safe.
Thanks for gathering this package.

Use case for the feature

I want to convert Country to Nationality in some parts of my application.

For example "Canada (CA) => Canadian" or "Iran (IR) => Iranian" or "Great Britain (GB) => British", etc....

I think there are much use cases for such a feature.

[WeeskyBDW]

Would it be pertinent to add both english name and native name of the nationality ? for exemple "Belgian" in english and "Belge" in native.