Decouple field info from GraphQL

[avin-kavish]

I'm using a multi-tiered service architecture. My resolvers do ACL checks and make requests to a business logic service layer, they don't load any data directly. I'd like to extract the required fields at the resolver and pass them between services via a more generic contract. Maybe a string array.

In order to do this the library would need to accept a selection of fields externally.