Key and pointer events delivered to popups are synthetic

https://codereview.qt-project.org/c/qt/qtbase/+/536709 has moved popup management from QApplication to QGuiApplication. It implements QWindowPrivate::forwardToPopup(), which forwards events to a popup using QCoreApplication::sendEvent().

That method doesn't set the QEvent::m_spont to true, which makes all key events appear synthetic, if delivered to a popup.