port framework_agreement_sourcing to 8.0

Dependencies:
- [x] merge https://github.com/OCA/vertical-ngo/pull/8
- [x] merge https://github.com/OCA/purchase-workflow/pull/34

Checklist:
- [x] make tests pass in v8
- [x] lint
- [x] functional test
In description bellow this comment:
s/generating/generated/
s/currences/currencies/