Tie DHP and FHIR more closely together

[torimcc]

The weaknesses of the pure API approach include things like not knowing who has permission to data at any given time (without maintaining state somewhere externally), and easily providing a unified composition of health data from across sources. We should highlight (and build if not productized) our ability to show these things to reinforce our differentiation.

We should consider providing support for this approach within DHP, since I believe it can be compatible with a blockchain-based approach (the comparison, I think, will be primarily DID vs Blockchain, and since DID is not a finalized standard, we have a bit of a lead)