TD: move all XML query handling to a single function

src/Mod/TechDraw/App/QDomNodeModel.cpp

@@ -28,6 +28,7 @@
 
 #include <QDomDocument>
 #include <QDomNode>
+#if QT_VERSION < QT_VERSION_CHECK(6,0,0)
 #include "QDomNodeModel.h"
 #include <QSourceLocation>
 #include <QUrl>
@@ -359,3 +360,4 @@ QXmlNodeModelIndex QDomNodeModel::nextFromSimpleAxis ( SimpleAxis axis, const QX
 
     return QXmlNodeModelIndex();
 }
+#endif