In Orders - add sorting on Vendor code

Steps to reproduce:

1. Login to Snapshot (as of 20200312) or to Chalmers (Edelweiss)

2. Go to Orders

3. Apply filters to get a result list

4. Click on column header Vendor code

Expected behaviour:
To have the list sorted by Vendor code (all other columns are sortable)

Actual results:
Cannot sort by Vendor code.

Additional information:
Our use case for this is that when going through and checking old open orders it's easier to do it vendor by vendor.
I'm writing this as a bug as it seems odd that this column only is not sortable.