Original PR description

**Issue**:
Sending a WhatsApp template with 10 or more variables can assign values to the wrong placeholders when the body contains mixed variable types, such as free text, field, or user name variables.
Templates containing only free-text variables are not affected.

**Reason**:
Meta consumes template parameters positionally, but for mixed variable types, Odoo built the parameter list using the template variable recordset order.
That order can differ from the numeric placeholder order, notably placing {{10}}, {{11}}, {{12}}... before {{1}}
when sending the message, as the payload parameters are not ordered by their numeric placeholder index.

**Fix:**
Sort body variables by their numeric placeholder index before preparing the Meta payload.

Task-6401501

Forward-Port-Of: odoo/enterprise#125671