Base: cleanup includes in *PyImp.cpp

Sort includes and implicitely add missing ones. While there
consistently explain where generated files some from.

src/Base/CoordinateSystemPyImp.cpp

@@ -22,14 +22,16 @@
 
 #include "PreCompiled.h"
 
-#include "AxisPy.h"
+#include "GeometryPyCXX.h"
+
+// generated out of CoordinateSystem.pyi
 #include "CoordinateSystemPy.h"
 #include "CoordinateSystemPy.cpp"
-#include "GeometryPyCXX.h"
+
+#include "AxisPy.h"
 #include "PlacementPy.h"
 #include "VectorPy.h"
 
-
 using namespace Base;
 
 // returns a string which represents the object e.g. when printed in python