Prefer LC_MONETARY when formatting currencies

[akx]

POSIX defines the LC_MONETARY category to be used for monetary formatting, hence Babel could be more standards-compliant in this regard.

Closes #1051 (supersedes it).

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.39%. Comparing base (2d8a808) to head (56ef7c7).
Report is 3 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1173      +/-   ##
==========================================
+ Coverage   91.37%   91.39%   +0.01%     
==========================================
  Files          27       27              
  Lines        4672     4681       +9     
==========================================
+ Hits         4269     4278       +9     
  Misses        403      403              

Flag	Coverage Δ
macos-14-3.10	90.42% <100.00%> (+0.03%)	⬆️
macos-14-3.11	90.36% <100.00%> (+0.03%)	⬆️
macos-14-3.12	90.57% <100.00%> (+0.03%)	⬆️
macos-14-3.13	90.57% <100.00%> (+0.03%)	⬆️
macos-14-3.8	90.29% <100.00%> (+0.04%)	⬆️
macos-14-3.9	90.35% <100.00%> (+0.03%)	⬆️
macos-14-pypy3.10	90.42% <100.00%> (+0.03%)	⬆️
ubuntu-24.04-3.10	90.45% <100.00%> (+0.03%)	⬆️
ubuntu-24.04-3.11	90.38% <100.00%> (+0.03%)	⬆️
ubuntu-24.04-3.12	90.60% <100.00%> (+0.03%)	⬆️
ubuntu-24.04-3.13	90.60% <100.00%> (+0.03%)	⬆️
ubuntu-24.04-3.8	90.31% <100.00%> (+0.04%)	⬆️
ubuntu-24.04-3.9	90.38% <100.00%> (+0.03%)	⬆️
ubuntu-24.04-pypy3.10	90.45% <100.00%> (+0.03%)	⬆️
windows-2022-3.10	90.44% <100.00%> (+0.01%)	⬆️
windows-2022-3.11	90.37% <100.00%> (+0.01%)	⬆️
windows-2022-3.12	90.59% <100.00%> (+0.01%)	⬆️
windows-2022-3.13	90.59% <100.00%> (+0.01%)	⬆️
windows-2022-3.8	90.41% <100.00%> (+0.01%)	⬆️
windows-2022-3.9	90.37% <100.00%> (+0.01%)	⬆️
windows-2022-pypy3.10	90.44% <100.00%> (+0.01%)	⬆️

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[tomasr8]

I'll take a look later today ;)

[tomasr8]

I just have two questions, the rest looks good to me :)