Sort profiles on extruder position before exporting

In the importer the extruders are sorted on extruder position. In the exporter they need to be in the same order.

Contributes to issue CURA-2655.

plugins/GCodeWriter/GCodeWriter.py

@@ -106,7 +106,7 @@ class GCodeWriter(MeshWriter):
         serialized = flat_global_container.serialize()
         data = {"global_quality": serialized}
 
-        for extruder in ExtruderManager.getInstance().getMachineExtruders(stack.getId()):
+        for extruder in sorted(ExtruderManager.getInstance().getMachineExtruders(stack.getId()), key = lambda k: k.getMetaDataEntry("position")):
             extruder_quality = extruder.findContainer({"type": "quality_changes"})
             if not extruder_quality:
                 Logger.log("w", "No extruder quality profile found, not writing quality for extruder %s to file!", extruder.getId())