Compile-time JSON-LD context expansion

[wyc]

If we were to build a JSON-LD library, I wonder how tenable would be the idea of resolving and expanding contexts into code via metaprogramming prior to compilation. We could assume the JSON files are in hand--I wonder if there would be any benefits from a safety and performance perspective, and how much binary bloat such a flag might add. Just a thought--this is likely one of those "someday maybe" features that we revisit when the need actually arises.

cc @clehner

[clehner]

Similar idea for JSON Schema: https://github.com/Marwes/schemafy/