workflows: new stage for error
- Adds new stage for objects that encountered an error.
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>
Reviewed-by: Jan Aage Lavik <jan.age.lavik@cern.ch>
Signed-off-by: Georgios Papoutsakis <georgios.papoutsakis@cern.ch>