[FIX] point_of_sale: fix pos_action access error

Steps to reproduce the bug:
- Log in as Admin
- Go to POS and open a session
- Select a customer for the order and complete the order
- Close the POS session
- Go to the associated customer to view their contact record
- Click the smart button for "Orders" > Admin can see POS orders for customer
- Log out, then log in as Demo
- Go to the contact and click the smart button for "Orders”

Problem:
An access error was raised:
`You are not allowed to access 'Action Window' (ir.actions.act_window) records.`

Only people in group Administration/Settings could read `action_pos_pos_form`

Solution:
To avoid this error, we should use `_for_xml_id`.

Opw-2734462

closes odoo/odoo#83214

X-original-commit: 05d17c9734249ed5a34ae84124bf14fd1b5f3b7c
Signed-off-by: Nicolas Lempereur (nle) <nle@odoo.com>
Signed-off-by: Djamel Touati (otd) <otd@odoo.com>

addons/point_of_sale/models/res_partner.py

@@ -36,7 +36,7 @@ class ResPartner(models.Model):
         '''
         This function returns an action that displays the pos orders from partner.
         '''
-        action = self.env.ref('point_of_sale.action_pos_pos_form').read()[0]
+        action = self.env['ir.actions.act_window']._for_xml_id('point_of_sale.action_pos_pos_form')
         if self.is_company:
             action['domain'] = [('partner_id.commercial_partner_id.id', '=', self.id)]
         else: