SW-20441 - Add event 'Shopware_Modules_Order_SaveOrder_FilterAttributes'
SW-20441 - Add event 'Shopware_Modules_Order_SaveOrder_FilterAttributes'

Add a filter event to easily add/modify the order attributes on saving
an order, similar to SW-17847 which added the event for the attributes
of the order detail(s).
Fixes https://github.com/shopware/shopware/pull/1360

oktupol/shopware,jochenmanz/shopware,simkli/shopware,k10r/shopware,simkli/shopware,k10r/shopware,oktupol/shopware,philippmahlow/shopware,jochenmanz/shopware,simkli/shopware,jochenmanz/shopware,philippmahlow/shopware,oktupol/shopware,oktupol/shopware,jochenmanz/shopware,k10r/shopware,philippmahlow/shopware,oktupol/shopware,simkli/shopware,simkli/shopware,philippmahlow/shopware,k10r/shopware,k10r/shopware,jochenmanz/shopware,philippmahlow/shopware