QTableView: honor spans when calculating height/width hint
QTableViewPrivate::heightHintForIndex()/widthHintForIndex() did not honor spans and therefore returned too big values.
Fixes: QTBUG-89116 Change-Id: I52948902b7eaaa27c092ed39da68950c3840e8e4 Pick-to: 5.15 Reviewed-by: Richard Moe Gustavsen richard.gustavsen@qt.io (cherry picked from commit 0e4cc2ac)