In order to be able to correctly size the chart type popup, we'll need
access to the total count or rows as a property that signals changes to
QML.
The hack to use rowCount() as the READ function requires that rowCount()
can be called without argument, therefore the addition of a default
parent.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
e610fb2481