Streamline use of CompositeSurface with SurfaceFilter (#3167)

Co-authored-by: Patrick Shriwise <[email protected]>
Co-authored-by: Paul Romano <[email protected]>

openmc/model/surface_composite.py

@@ -33,6 +33,10 @@ def rotate(self, rotation, pivot=(0., 0., 0.), order='xyz', inplace=False):
             setattr(surf, name, s.rotate(rotation, pivot, order, inplace))
         return surf
 
+    @property
+    def component_surfaces(self):
+        return [getattr(self, name) for name in self._surface_names]
+
     @property
     def boundary_type(self):
         return getattr(self, self._surface_names[0]).boundary_type