QmlDesigner: Add pivot point visualization line to 3D edit view

A line connecting the pivot point and object center is added to
3D edit view.

Change-Id: Ic265e9a3ab2895761cc92b94c778d68509ef36f1
Fixes: QDS-1474
Reviewed-by: Thomas Hartmann <thomas.hartmann@qt.io>

src/tools/qml2puppet/qml2puppet.qbs

@@ -215,6 +215,8 @@ QtcTool {
             "editor3d/gridgeometry.h",
             "editor3d/selectionboxgeometry.cpp",
             "editor3d/selectionboxgeometry.h",
+            "editor3d/linegeometry.cpp",
+            "editor3d/linegeometry.h",
             "qml2puppetmain.cpp",
         ]
     }