fix: JsonFhirFormatter summary parameter not set
fix: JsonFhirFormatter summary parameter not set

* In the method WriteToStreamAsync, the summary argument of
  FhirJsonSerializer.Serialize was not set, even though we retrieved
  SummaryType from the request.
* After this update JsonFhirFormatter is using SummaryType retrieved
  from the request the same way XmlFhirFormatter does.

furore-fhir/spark,furore-fhir/spark,furore-fhir/spark