Reorder the includes following the coding conventions.
Remove unneeded includes.
Add needed includes to avoid Transitive includes.
QGestureEvent is passed by a pointer in the gestureEvent method in
mandelbrotwidget.h. So, we do not really need to include the header.
Instead, forward-declare QGestureEvent class in a namespace.
Task-number: QTBUG-108861
Pick-to: 6.5
Change-Id: I48cfd663bf98350281ef7f31e6c0ef3e301a08ca
Reviewed-by: Dennis Oberst <dennis.oberst@qt.io>
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
(cherry picked from commit a4d7a4ccb39daa86ee2ef23b1408344822ae7c16)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
a88f26f7e4