update mapping json obeservsi dan diagnosis report

internal/satusehat/usecase/observation/mapper.go

@@ -95,6 +95,12 @@ func MapRequestToFHIR(req ObservationRequest) satusehat.FHIRPayload {
 		payload.Set("bodySite", map[string]interface{}{"coding": []map[string]interface{}{coding}})
 	}
 
+	if req.ServiceRequestID != "" {
+		payload.Set("basedOn", []map[string]interface{}{
+			{"reference": "ServiceRequest/" + req.ServiceRequestID},
+		})
+	}
+
 	switch {
 	case req.ValueQuantityValue != nil:
 		sys := req.ValueQuantitySystem