Add quickfix to add a Qt6 Binding to an existing Q_PROPERTY

See https://www.qt.io/blog/property-bindings-in-qt-6. A Quickfix to generate the new thinks like here:

class MyObject : public QObject
{
    Q_PROPERTY(int x GET x SET setX BINDABLE bindableX)
    // the line below was “int xData;” in Qt 5
    Q_OBJECT_BINDABLE_PROPERTY(MyObject, int, xData)
public:
    int x() { return xData; }
    void setX(int x) { xData = x; }
    QBindable<int> bindableX() { return &xData; }
};