Add a feature switch for rudderc use during generation
We stil a lot of problems and missing features for rudderc, and they are not always triggering and error and thus the fallback to old still generation.
We need to be able to disable rudderc at least for dsc agent, and perhaps for all to workaround these cases.
So we need to add a feature switch with 3 states:
- never use rudderc (disabled)
- try rudderc only for unix policies
- always try rudderc
Option 2 would be the default on 7.0.