Enable settlement of trade whose DSC has 0 stage amount(s)

[jijordre]

Description

As currently implemented it is possible to start a DSC on a trade and propose stage amount(s) of 0. However, when settling this trade the settlement call fails. The reason being that ClientFund.stage() is set to revert with stage amount that is not strictly positive.

This issue describes the enablement of settlement of trade whose DSC proposes stage amount(s) of 0. This can be done by only calling ClientFund.stage() when the respective stage amount is strictly positive.

Definition of done

• DriipSettlementByTrade has been updated
• Unit tests have been updated

Details & Questions

Depends on

• Enable settlement of payment whose DSC has 0 stage amount #449