Allow code field to be calculated

We've heard from some Studios that it would be useful to have the entity code field values populated by a calculation. (At the moment, they're text fields, which have to be populated manually, or via a script). 

The examples we've seen usually involve a concatenation of linked fields on the entity (currently not supported with calculated fields). 

Example for the Shot `code` field: CONCAT({project}_{sequence}_ShotCode)

If this is something that would be useful for your studio, please feel free to add your +1 vote, and use-case.