QHeaderView::logicalIndexAt(const QPoint &apos) - QPointF should also be supported

E.g. with QHoverEvent.

But applies to alle events that had 'QPoint pos()' and now have 'QPointF position()'.

To call logicalIndexAt(), we now need to convert from QPointF to QPoint with toPoint().

However, if Qt moves from QPoint usage to QPointF usage it would be logical to also provide  QPointF equivalents of the functions that are regularly used with QPoint.