[Sketch] App P - End: remove unused headers

- also some sorting

src/Mod/Sketcher/App/SketchGeometryExtension.cpp

@@ -22,15 +22,14 @@
 
 #include "PreCompiled.h"
 
-#include <Base/Writer.h>
 #include <Base/Reader.h>
-
+#include <Base/Writer.h>
 #include <Mod/Sketcher/App/SketchGeometryExtensionPy.h>
 
 #include "SketchGeometryExtension.h"
 
-using namespace Sketcher;
 
+using namespace Sketcher;
 
 //---------- Geometry Extension
 constexpr std::array<const char *, InternalType::NumInternalGeometryType> SketchGeometryExtension::internaltype2str;