Add ChallengeByOrderEvent to {Driip,Null}SettlementChallengeByTrade

[jijordre]

Description

An event for the successful challenge of a driip or null by order is currently emitted only by the corresponding DriipSettlementDisputeByTrade/NullSettlementDisputeByTrade. However, the external entry point for the submission of a order candidate is through the DriipSettlementChallengeByTrade/NullSettlementChallengeByTrade. An event for the successful submission of order candidate should thus also be added to the latter.

This issue describes the addition of such events.

Definition of done

• DriipSettlementChallengeByTrade has been updated to emit event upon the successful challenge by order
• NullSettlementChallengeByTrade has been updated to emit event upon the successful challenge by order
• Unit tests have been updated

Details & Questions

Depends on

[jijordre]

Closed by #414.