[TD] final fix of compilation after #8141

- in DimensionValidators.h the declarations must not be with TechDrawExport
- add missing precompiled headers

- also fix too long lines (fixed by clang)
- also some re-sorting
- also remove unused headers

src/Mod/TechDraw/Gui/ViewProviderDrawingViewExtension.h

@@ -28,6 +28,7 @@
 #include <Gui/ViewProviderExtensionPython.h>
 #include <Mod/TechDraw/TechDrawGlobal.h>
 
+
 namespace TechDrawGui
 {
 class ViewProviderDrawingView;