fix LR sourcing with a PR

* use the correct API version in the wizard:
  the code would use self.pool.get which returns an old-API model
  and then use it through the new API

* add a yaml test for this sourcing flow (long because we need to manually
  process the whole PR)

* fix various isssues with new API use:
  - cannot write on a recorset with > 1 records
  - confusions with bits expecting records / ids
fix validation of a cost estimate
do not override function field for purchase line

It does not seem to make much difference from the original one in
logistic_requisition.
remove onchange agreement

The agreement field should already have a domain: no need to check with
an onchange that a consistent choice is made.
lint
use the correct API version

the code would use self.pool.get which returns an old-API model
and then use it through the new API
fix regression because of a comma too many
Merge branch 'port_framework_agreement_sourcing' into agreement_sourcing+logistic_requisition
Merge branch '8.0-logistic_requisition' into agreement_sourcing+logistic_requisition

Conflicts:
	.travis.yml