Reduce overhead for including qguiapplication.h by splitting
up qnativeinterface.h into a public and a private part.
[ChangeLog][Potentially Source-Incompatible Changes] The
qguiapplication.h header no longer implicitly includes
qloggingcategory.h. If your code depends on the transitive
include, explicitly include <QLoggingCategory> where needed.
Pick-to: 6.2
Task-number: QTBUG-97601
Change-Id: Ic02327a1c3092e21730160af5c59a9d58dc1239c
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
b99adf7a81