Waterwijzer: Add BRP_CODE attribute to functions

As a project creator and analyst, I would like the functions in the Tygron Platform to have BRP_CODEs as well (rather than just the constructions), so that I can assign actions and/or replace existing constructions with new constructions relevant to the Waterwijzer, and the Waterwijzer calculation will just work without manually having to determine and set the appropriate BRP_CODE values.