[core] Respect system language order

Signed-off-by: Yannik Bloscheck <git@yannikbloscheck.com>

platform/preferred_languages.hpp

@@ -25,6 +25,7 @@ std::string GetCurrentMapTwine();
 std::string Normalize(std::string_view lang);
 std::string GetCurrentNorm();
 std::string GetCurrentMapLanguage();
+std::vector<int8_t> GetPreferredLangIndexes();
 
 buffer_vector<std::string, 4> const & GetSystemPreferred();
 }  // namespace languages