Refactor: give the detailed `UserGeolocation` object to overlay component

[eastandwestwind]

          nit: architecturally it would make more sense to me to give the detailed `UserGeolocation` object to the overlay, since it's structured data (country, region, location string). That would make it easier to, for example, show a country flag indicator on the modal or a "Your detected location: <blah>" component.

The coercion to the flattened ${country}_${region} string feels like an API concern.

But that's not needed here yet - just a consideration for further tweaks?

Originally posted by @NevilleS in https://github.com/ethyca/fides/pull/3361#discussion_r1207027452

[mfbrown]

@NevilleS @eastandwestwind Is this ticket a must have for sprint 12?

[rsilvery]

@mfbrown is this still an issue?