Allow separation of SCL modules/functions/definitions into system and user
The idea would be that the module {}
header of SCL modules could be used to define all or parts of the module as system entities. This would mean that those entities would not be shown in:
- SCL documentation browser
- SCL module search
- SCL definition search
Essentially system entities would be hidden from the user in all possible ways. This would be useful for hiding such modules from the user that are not intended for user consumption in the first place.