Splitting the method `_get_order_lines` will allow making it inheritable, this way more order line fields can be added and expand them easily and avoid having to overwrite it. closes odoo/odoo#105858 X-original-commit: 457624160f03c28e9b90d14fb4c56fe2f7fabeed Signed-off-by: Trinh Jacky (trj) <trj@odoo.com>