Enable QLineF::intersects on Qt version 5.14.0 (#9095)

function "QLineF::IntersectionType QLineF::intersects(const QLineF &line, QPointF *intersectionPoint) const" was introduced in Qt 5.14, and QLineF::intersect is obsolete.

see also:
https://doc.qt.io/qt-5.14/qlinef-obsolete.html
https://doc.qt.io/qt-5.14/qlinef.html#intersects