Enhancement: Widget visibility config by country

### Impacted plugin

Jetpack

### What

Show Widget by Country

### How

Hi,
I'm going to ask you to add something to Jetpack's Widget Visibility feature that .

Show or hide by country.

Maybe it may seem unnecessary to some of you, but it may come a time when it is very necessary.

Thanks.

Start by locating Jetpack's Widget Visibility feature and reviewing how its current configuration is represented. Clarify the country-selection behavior and acceptance criteria before implementation; done means widgets can be shown or hidden by country.

Written by the indexing model from the issue text.