Feature/add bank id on `res_partner_bank` creation

• Commit 1: Use an already implemented method from base_bank_from_iban if the created res_partner_bank has no bank_id associated.

The method was only used "on.change" which doesn't apply in instance creation. https://www.odoo.com/documentation/14.0/reference/orm.html

• Commit 2: Fix typo in class name