[Accounting] invoicing access rights

Hello,

Gived some access rights for validate and pay invoice  to invoicing and payment user.

- Task: https://www.odoo.com/web#id=6820&view_type=form&model=project.task&menu_id=3942&action=327
- Pad: https://pad.odoo.com/p/openerp-project.task-1W58J32RBF.

Thanks,
@cod-odoo