[TD]clazy warnings and duplicate setter/getter

- clazy warning re missing Q_OBJECT

- include TechDrawGlobal.h in headers

- resolve duplicate setter/getters

src/Mod/TechDraw/App/DrawViewDimExtent.h

@@ -23,6 +23,8 @@
 #ifndef _TechDraw_DrawViewDimExtent_h_
 #define _TechDraw_DrawViewDimExtent_h_
 
+#include <Mod/TechDraw/TechDrawGlobal.h>
+
 #include <tuple>
 
 #include <App/DocumentObject.h>
@@ -36,6 +38,7 @@ namespace TechDraw {
 class TechDrawExport DrawViewDimExtent : public TechDraw::DrawViewDimension
 {
     PROPERTY_HEADER_WITH_OVERRIDE(TechDraw::DrawViewDimExtent);
+    Q_OBJECT
 
 public:
     /// Constructor