chore(locale): change uk_country to state

[matthewmayer]

part of #1944

Since the decision was to use location.state() for 1st level admin regions and location.county() for 2nd level admin regions

It would be confusing to use state() for counties in en_GB.

Instead, move the currently unused/inaccessible (except via faker.fake) uk_country as the 1st level admin area. This would be more intuitive for
British users.

[codecov]

Codecov Report

Merging #1989 (5bacc76) into next (f890d62) will decrease coverage by 0.01%.
The diff coverage is 100.00%.

Additional details and impacted files

@@            Coverage Diff             @@
##             next    #1989      +/-   ##
==========================================
- Coverage   99.62%   99.62%   -0.01%     
==========================================
  Files        2458     2458              
  Lines      239905   239905              
  Branches     1278     1278              
==========================================
- Hits       238999   238996       -3     
- Misses        883      886       +3     
  Partials       23       23              

Impacted Files	Coverage Δ
src/locales/en_GB/location/state.ts	100.00% <ø> (ø)
src/locales/en_GB/location/index.ts	100.00% <100.00%> (ø)

... and 2 files with indirect coverage changes