Part: move model check to separate function

This is to avoid code duplication.

src/Mod/Part/App/FeaturePartCommon.cpp

@@ -40,6 +40,11 @@
 
 using namespace Part;
 
+namespace Part
+{
+    extern void throwIfInvalidIfCheckModel(const TopoDS_Shape& shape);
+}
+
 PROPERTY_SOURCE(Part::Common, Part::Boolean)
 
 
@@ -101,17 +106,7 @@ App::DocumentObjectExecReturn *MultiCommon::execute()
         throw Base::RuntimeError("Resulting shape is null");
     }
 
-    Base::Reference<ParameterGrp> hGrp = App::GetApplication()
-                                             .GetUserParameter()
-                                             .GetGroup("BaseApp")
-                                             ->GetGroup("Preferences")
-                                             ->GetGroup("Mod/Part/Boolean");
-    if (hGrp->GetBool("CheckModel", false)) {
-        BRepCheck_Analyzer aChecker(res.getShape());
-        if (!aChecker.IsValid()) {
-            return new App::DocumentObjectExecReturn("Resulting shape is invalid");
-        }
-    }
+    throwIfInvalidIfCheckModel(res.getShape());
 
     if (this->Refine.getValue()) {
         res = res.makeElementRefine();