fix(nets): use GetNetClassName() instead of GetClassName() on NETINFO_ITEM

NETINFO_ITEM objects don't have a GetClassName() method, causing
an AttributeError crash when listing nets. The correct method is
GetNetClassName() which returns the net class name string.

python/commands/routing.py

@@ -509,7 +509,7 @@ class RoutingCommands:
                         {
                             "name": net.GetNetname(),
                             "code": net.GetNetCode(),
-                            "class": net.GetClassName(),
+                            "class": net.GetNetClassName(),
                         }
                     )