Fix QtQuickDialogWrapper dialog not being usable in konsole
Patch provided by David Edmundson.
Issue is QGuiApplicationPrivate::showModalWindow
it marks every other non-modal window as blocked, including new windows.
when we focus the new dialog at a wayland/X level Qt gets it, but in it's own internal dispatching ignores that and sends it to the modal window
Qt is smart enough to handle child windows appropriately, but only if it knows about them. Having a transient parent should take care of this. We should have this anyway as that will fix some window placement bugs.