[IMP] account: credit note usability

Task 2038326

* Tick the credit note sequence by default on the customer invoices and vendor bills journals
* Write Customer Invoice/Vendor Bill/Credit Note/Customer refund at the top of the document
* The reference field should be printed on the credit note pdf (interesting because it gives source and reason)
* If the document is a credit note, there shouldn't be any payment information on the pdf (the customer doesn't have to pay you) (currently you see the "payment communication" the customer is supposed to use)
* Rename Credit Note to Refund on dashboard
* Add tooltip on payment widget

closes odoo/odoo#35231

Signed-off-by: Cedric Snauwaert (csn) <csn@openerp.com>