[Part] Geometry*PyImp.cpp: remove unneeded includes

- also sort includes

src/Mod/Part/App/GeometryStringExtensionPyImp.cpp

@@ -20,18 +20,16 @@
  *                                                                         *
  ***************************************************************************/
 
-
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
 # include <sstream>
 #endif
 
-#include "GeometryDefaultExtension.h"
-
 #include "GeometryStringExtensionPy.h"
 #include "GeometryStringExtensionPy.cpp"
 
+
 using namespace Part;
 
 // returns a string which represents the object e.g. when printed in python