feat(LOY-156): Improve language handling and localization in profile page
* feat(LOY-156): Improve language handling and localization in profile page
* refactor(LOY-156): Improve language display using Intl.DisplayNames
* feat(LOY-156): Enhance country display with localized country names
* refactor(LOY-156): Move countries data to a dedicated constants file & more type safe country mapping
* feat(LOY-156): Update isValidLang to use languageSchema + German translation for membership terms and conditions
* chore(LOY-156): language handling in profile component
Approved-by: Christian Andolf