[FIX] Invoice & SO reports: show payment term & fiscal position notes

Follows this commit: 3d88a60
And partly anticipates this task:
Task link: https://www.odoo.com/web#id=9673&view_type=form&model=project.task&action=327
Branch link: https://github.com/odoo-dev/odoo/tree/master-reports_alignment_issues-rda
shouldn't this be `o.fiscal_position.note` as well?