This is a simple backend based on navigator.languages,
which gives us a prioritized list of languages in the
form '["en-US", "zh-CN", "ja-JP"]'.
Use this to implement QSystemLocale::query() for UILanguages
and QSystemLocale::fallbackLocale().
Register an event handler for the native QWindow:languagechange
event in the QSystemLocale constructor. This event handler
stays active for the lifetime of the QSystemLocale object.
Task-number: QTBUG-116613
Change-Id: Ibd176748377e891b63a3f1d57605af0c2a49edb3
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@qt.io>
63fc3175b4