Windows: Let QLocale::uiLanguages() return all preferred languages

QLocale::uiLanguages() on Windows does seem to only return the system UI language, not the full list of 'preferred' languages that can be set in the Windows system:

This is because of the Win32 API used. QLocale uses GetUserPreferredUILanguages() , which seem to return only one or two languages (see also https://stackoverflow.com/questions/52849233/getuserpreferreduilanguages-never-returns-more-than-two-languages ).

An alternative is to use the WinRT API, GlobalizationPreferences::Languages().

Output from attached test app:

QLocale()::uiLanguages() QList("en-US")
win32_uilanguages QList("en-US")
winrt_uilanguages QList("de-DE", "en-GB", "en-US", "en-DE")

Can we consider supporting the winrt API?