Locale setting UI test

This is testing another new subsystem for the new Setting system & UI in Resonite - custom subcategories for settings. In this case, the Locale settings has a method that enumerates available locales as data feed items, to provide an UI interface to select desired locale. To allow this to function as well, ability to proxy methods with an argument (in this case a locale code) has been implemented. Support development at: More at: