Column properties not correctly supported for QtQuick 2.7 & 2.8

QML component Column added support for positioningComplete signal in Qt 5.9. From the Qt 5.9 documentation (https://doc-snapshots.qt.io/qt5-5.9/qml-qtquick-column.html), it is necessary to import QtQuick 2.7.

When using import QtQuick 2.7 or import QtQuick 2.8, Qt Creator throws error M16: Invalid property name "onPositioningComplete". (M16).

If I ignore this as a lint error and run the code, I get the error: "Column.onPositioningComplete" is not available in QtQuick 2.6"

Only when importing QtQuick 2.9 or higher does this error go away.