[FIX] account: display qr_code

Steps to reproduce:
- activate qr-code
- create a contact with a valid account and activate "send money"
- create a bill for this customer
- register the payment
- view the payment

Issue:
The QR-code is displayed as plain text

Cause:
The commit 688986f deleted the use of markup and the field qr_code is still as char and cannot be Markup'ed by the ORM

opw-3293289

closes odoo/odoo#122553

X-original-commit: 61a519aa5d62891fd8bda232ae09b48381786cf8
Signed-off-by: Olivier Colson (oco) <oco@odoo.com>

addons/account/models/account_payment.py

@@ -39,7 +39,7 @@ class AccountPayment(models.Model):
         readonly=False, store=True,
         tracking=True,
         compute="_compute_is_internal_transfer")
-    qr_code = fields.Char(string="QR Code URL",
+    qr_code = fields.Html(string="QR Code URL",
         compute="_compute_qr_code")
     paired_internal_transfer_payment_id = fields.Many2one('account.payment',
         help="When an internal transfer is posted, a paired payment is created. "