Rule Schema to pull data from library sources

The Rule schema should pull some of its data from library or other external sources, for example:
- Allowed Scope DDF classes/entities should come from the USDM model
- Allowed Scope SDTMIG classes/domains should come from the SDTM/SDTMIG model or CT Domain list

This may require changes in both the engine schema and the rule editor api's schema generator