post https://api.qogita.com/shipmentgroups//add_details/
- Retrieve shipment group instance from DB by qid and
perform necessary checks. - Validate request data using request_serializer_class
- Check shipment group has at least one outbound
- Check request has appropriate number of codes for
number of outbounds in shipment group - Update shipping details for all outbounds in group
- Create events for shipment group and for each outbound
- Re-retrieve shipment group instance from db
- Return representation using response_serializer_class