Add document originator feature from purchase orders to sales orders

In purchase orders you have the option to set the document originator as someone else from a drop down list. This would be helpful to be a feature in sales orders as the person who takes the order isn't always who inputs it into the system. Currently we have to manually overtype and change the name which also means you can't see who actually put the order onto the system. This has to be done multiple times if an order starts as a proforma as what you set in a proforma changes when you then convert to a sales order so you have to change it again