[TD] remove unused headers (#8155)

* [TD] remove unused headers

- also some sorting
- also improve readability by not using an abbreviation (we consistently don't abbreviate class names)

src/Mod/TechDraw/Gui/ViewProviderTemplateExtension.cpp

@@ -21,19 +21,10 @@
  ***************************************************************************/
 
 #include "PreCompiled.h"
-#ifndef _PreComp_
-# include <QMessageBox>
-#endif
 
-#include <App/Document.h>
 #include <App/DocumentObject.h>
-#include <Base/Console.h>
-#include <Base/Tools.h>
-#include <Mod/TechDraw/App/DrawPage.h>
-#include <Mod/TechDraw/App/DrawTemplate.h>
 
 #include "ViewProviderTemplateExtension.h"
-#include "ViewProviderPage.h"
 #include "ViewProviderTemplate.h"