Add Column Portal Type If Listbox Contains Multiple Types
Always display the translated_portal_type of documents in the listbox of
a module if this module can contain different portal types.
If a listbox in ERP5 is supposed to display objects having different
portal types, then a portal type column is needed in the listbox to show this
information. What should be displayed is always the "translated_portal_type"
so that the forms can be automatically localised.