do not forward QGraphicsItem::MousePressEvent when zoom selection is used.

do not forward QGraphicsItem::MousePressEvent when zoom selection is used. So the selection does not change. So it is possible to change the item over the project explorer and the action is applied on its ranges. It makes it more intuitive.

Previously: When zoom selection was selected and it was clicked into the plot the plot was selected and at the end it will be switched back. But in this case it is not possible to select a different item in the project explorer (possible, but the action handles still the ranges of the previous item).

@asemke Is it fine ignoring?