Import: modernize C++: return braced init list

src/Mod/Import/App/ImportOCAF2.cpp

@@ -991,7 +991,7 @@ TDF_Label ExportOCAF2::findComponent(const char *subname, TDF_Label label, TDF_L
         Handle(XCAFDoc_GraphNode) ret;
         if(labels.Length() && (FindSHUO(labels,ret) || aShapeTool->SetSHUO(labels,ret)))
             return ret->Label();
-        return TDF_Label();
+        return {};
     }
     TDF_LabelSequence components;
     TDF_Label ref;
@@ -1018,7 +1018,7 @@ TDF_Label ExportOCAF2::findComponent(const char *subname, TDF_Label label, TDF_L
             }
         }
     }
-    return TDF_Label();
+    return {};
 }
 
 void ExportOCAF2::setupObject(TDF_Label label, App::DocumentObject *obj,
@@ -1191,7 +1191,7 @@ TDF_Label ExportOCAF2::exportObject(App::DocumentObject* parentObj,
     if(!obj || shape.isNull()) {
         if (obj)
             FC_WARN(obj->getFullName() << " has null shape");
-        return TDF_Label();
+        return {};
     }
 
     //sub may contain more than one hierarchy, e.g. Assembly container may use

src/Mod/Import/App/StepShapePyImp.cpp

@@ -31,7 +31,7 @@ using namespace Import;
 // returns a string which represents the object e.g. when printed in python
 std::string StepShapePy::representation() const
 {
-    return std::string("<StepShape object>");
+    return {"<StepShape object>"};
 }
 
 PyObject *StepShapePy::PyMake(struct _typeobject *, PyObject *, PyObject *)  // Python wrapper

src/Mod/Import/App/dxf/ImpExpDxf.cpp

@@ -99,7 +99,7 @@ gp_Pnt ImpExpDxfRead::makePoint(const double* p)
         sp2 = sp2 * optionScaling;
         sp3 = sp3 * optionScaling;
     }
-    return gp_Pnt(sp1,sp2,sp3);
+    return {sp1,sp2,sp3};
 }
 
 void ImpExpDxfRead::OnReadLine(const double* s, const double* e, bool /*hidden*/)

src/Mod/Import/Gui/AppImportGuiPy.cpp

@@ -534,7 +534,7 @@ private:
         auto vp = Gui::Application::Instance->getViewProvider(obj);
         if(vp)
             return vp->getElementColors(subname);
-        return std::map<std::string,App::Color>();
+        return {};
     }
 
     Py::Object exportOptions(const Py::Tuple& args)