Shortcuts don't work for QWidget that embedded to QGraphicsView

To reproduce the issue:

1. Create any QWidget and add QAction with shortcut to it.

2. Create QGraphicsView, QGraphicsScene

3. Add QWidget (with action) to the scene.

4. Run application, set focus to QWidget and try to activate the QAction by shortcut. Will fail.

If the QWidget will be added into the regular QMainWindow shortcut works fine.