(1) adding sample codes example and (2) updating codes best practices document with the CODES example

Updating the workload test to use the config file for the 'bgp_io_workload' and 'test' workload types. Loads the workload file for the bgp_io_workload type. Tests for remaining operations are to be added

The Bison code breaks in Bison 2.7 or newer.  We don't have any changes
planned for the parser itself in the near term, so this commit adds a
version of the parser generated with Bison 2.5 back to the repo for now.