Core: Prove that shipment weights is calculated correctly
Core: Prove that shipment weights is calculated correctly

Refs SHOOP-2494

suutari/shoop,shoopio/shoop,shawnadelic/shuup,shawnadelic/shuup,suutari-ai/shoop,hrayr-artunyan/shuup,shoopio/shoop,suutari-ai/shoop,suutari-ai/shoop,hrayr-artunyan/shuup,suutari/shoop,shawnadelic/shuup,hrayr-artunyan/shuup,suutari/shoop,shoopio/shoop