[Base] Move XdbfLocale to xbox.h as XLanguage, let STFS headers use it

Renamed to XLanguage because AFAIK locale on Xbox is a different concept involving countries, this enum only involves languages though.

src/xenia/emulator.cc

@@ -714,7 +714,7 @@ X_STATUS Emulator::CompleteLaunch(const std::filesystem::path& path,
           module->memory()->TranslateVirtual(resource_data), resource_size);
       if (db.is_valid()) {
         // TODO(gibbed): get title respective to user locale.
-        title_name_ = db.title(kernel::util::XdbfLocale::kEnglish);
+        title_name_ = db.title(XLanguage::kEnglish);
         if (title_name_.empty()) {
           // If English title is unavailable, get the title in default locale.
           title_name_ = db.title();