Add costs fields to Worker model, admin and serializer

closes #1891 (closed)

changed milestone to %Arkindex 1.7.2

requested review from @erouchet

assigned to @mlbonhomme

added 2 commits

• ce317172 - 1 commit from branch release-1.7.2
• fcc50b04 - Add costs fields to Worker model, admin and serializer

Compare with previous version

mentioned in merge request frontend!1834 (merged)

added 2 commits

• e5e095b5 - Document the currency
• e05dd125 - Explicit field names in the admin

Compare with previous version

enabled an automatic merge when all merge checks for e05dd125 pass

merged