CO-3832 : add constrain on invoice validation (#1431)
CO-3832 : add constrain on invoice validation (#1431)

* CO-3832 : add constrain on invoice validation

- Add a "raise UserError" when another account.invoice already is already open with the same transaction_id

* adapt code according to the pr comments

* fix accroding to pr
eicher31/compassion-switzerland,CompassionCH/compassion-switzerland,eicher31/compassion-switzerland,eicher31/compassion-switzerland,CompassionCH/compassion-switzerland,CompassionCH/compassion-switzerland