Integrate FHIR packages for easier communication

[nstrelow]

Recently new dart fhir packages have been created: https://pub.dev/publishers/fhirfli.dev/packages

These are not mine, but maybe this is viable for communicating efficiently with FHIR servers in flutter.

[im-Amitto]

@nstrelow sounds like a great plan, I remember adding fhir was one of the gsoc project last year so just check that and see how we can help the UX using an mobile app.