Also add test to check that calling QQuickItem::grabToImage() works
The QSharedPointer type is added in the QtQuick typesystem file
and not in QtCore to minimize the surface of issues that might come up,
as well as because that's the only reasonable use case of QSharedPointer
in the public API so far.
The commit was missing in 5.9 branch after repo merge.
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>