Add Irish (ga-ie) locale support

[mklinzing]

This pull request adds Irish (ga_IE) localization support to Stumpless by introducing translated message strings and the corresponding locale configuration. The goal is to expand language coverage while maintaining consistency with existing localization patterns and conventions. This change resolves Issue #117 reported on GitHub.

Guidelines for Contributing.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.91%. Comparing base (cd221c7) to head (d8d9141).

Additional details and impacted files

@@           Coverage Diff           @@
##           latest     #553   +/-   ##
=======================================
  Coverage   90.91%   90.91%           
=======================================
  Files          47       47           
  Lines        4547     4547           
  Branches      601      601           
=======================================
  Hits         4134     4134           
  Misses        273      273           
  Partials      140      140           

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[goatshriek]

Thanks very much for putting this together! Just one update to the header and a few lines that need to be broken up so that they aren't too long (see the static analysis run), and then this should be good to go!

[goatshriek]

Update this header guard to use __STUMPLESS_PRIVATE_CONFIG_LOCALE_GA_IE_H