[R&D] How do we support PWA architecture with the FHIR SDK data access library

[fredhersch]

The goal here is to figure out how the FHIR SDK could have value for the community of developers using PWAs.

1. Define potential use cases that we can validate -(@roboton)
2. Explore technical approaches (e.g. on device access to the FHIR SDK for storage and data-access)
3. Define a POC ideally with an existing provider (e.g. medic CHT)
4. Develop POC

cc: @jingtang10

[roboton]

Currently the Medic Mobile CHT architecture is:

XLSForm gets turned into an XForm which is rendered into html by Enketo and presented to the UI via AngularJS
There's a client-side, offline resilient PouchDB (javascript implementation of CouchDB, a NoSQL document oriented DB) that stores these XLSForms and their saved instances as json objects and syncs them with a server-side CouchDB when online.

[roboton]

If we supported XForms, we could simply rely on Enketo for the web rendering (this is what Medic uses): https://enketo.org/develop/