Provide an update to make_macros.py script to use python3

[MartinCruzAtDaikin]

While using better-enums, I had the need to extend the limits to use a maximum of 512 enumerators and enumerator entries of 40-characters length, so I follow the procedure to create an enum_macros.h with extended limits.
For internal reasons, I have to use python3, so current script is giving me issues.
I have modified original script to use python, and I want to create a task to check that in and go through pull request.