[FIX] account: payment state when reconciling refund with bank statement

**Summary**

Currently, if you create a credit note/refund and reconcile it directly
with a statement line (without creating a payment), the
credit note/refund ends up in the "reversed" payment state, whereas it
should be "paid".

**Setup**

- Install `account_accountant`

**Steps to reproduce**

- create a credit note/refund and confirm it
- create the corresponding bank statement line
- reconcile those two

Go back to the credit/refund not, you should see that its payment state
is "reversed", instead of "paid".

opw-3328830

closes odoo/odoo#123272

Signed-off-by: Laurent Smet (las) <las@odoo.com>