Private billing: Adding "compte à recevoir" to the Payment Method options

– Affected user(s): MOA

– Task affected: The customer requests that "compte à recevoir/account receivable" be added to the payment method options. Because "à payer/Payable" does not allow to close the invoice.

– Impact : When trying to close an invoice indexed as receivable.

– Current state The client has to track manually her invoices.