[FIX] pos_self_order: prevent error with online payment method

Prior to this commit, using an online payment method with an image in
self-ordering mode resulted in an issue preventing the opening of the
mobile menu. The specific error encountered was:
`TypeError: Object of type bytes is not JSON serializable`

This issue arose due to the image field being of type bytes. Since the
image field is not necessary for self-ordering, this commit addresses
the problem by preventing the loading of the image for a payment
method, resolving the serialization error.

opw-3624798

closes odoo/odoo#151388

Signed-off-by: Joseph Caburnay (jcb) <jcb@odoo.com>

addons/pos_online_payment_self_order/models/pos_config.py

@@ -18,8 +18,7 @@ class PosConfig(models.Model):
 
     def _get_self_ordering_data(self):
         res = super()._get_self_ordering_data()
-        payment_search_params = self.current_session_id._loader_params_pos_payment_method()
-        payment_methods = self.self_order_online_payment_method_id.read(payment_search_params['search_params']['fields'])
+        payment_methods = self._get_self_ordering_payment_methods_data(self.self_order_online_payment_method_id)
         res['pos_payment_methods'] += payment_methods
         return res
 

addons/pos_self_order/models/pos_config.py

@@ -331,10 +331,15 @@ class PosConfig(models.Model):
             }
         return printerData
 
+    def _get_self_ordering_payment_methods_data(self, payment_methods):
+        excluded_fields = ['image']
+        payment_search_fields = self.current_session_id._loader_params_pos_payment_method()['search_params']['fields']
+        filtered_fields = [field for field in payment_search_fields if field not in excluded_fields]
+        return payment_methods.read(filtered_fields)
+
     def _get_self_ordering_data(self):
         self.ensure_one()
-        payment_search_params = self.current_session_id._loader_params_pos_payment_method()
-        payment_methods = self._get_allowed_payment_methods().read(payment_search_params['search_params']['fields'])
+        payment_methods = self._get_self_ordering_payment_methods_data(self._get_allowed_payment_methods())
         default_language = self.self_ordering_default_language_id.read(["code", "name", "iso_code", "flag_image_url"])
 
         return {