Validator throws errors for references that only have identifiers instead of an direct resource reference

[mmsmits]

While updating the SDK to 5.10.1, a unit test fails in the validator-api:

This unit test (RunValidateTestSuite (issue-165) )contains a reference looking like this:

<payor>
  <identifier>
    <system value="http://fhir.de/NamingSystem/arge-ik/iknr" />
    <value value="101575519" />
  </identifier>
  <display value="TK" />
</payor>

As you can see, it does not have a direct reference at, but just an identifier and a display.
After upgrading, the validator now throws the following error;

[ERROR] Instance failed constraint ref-1 "SHALL have a contained resource if a local reference is provided" (at Bundle.entry[6].resource[0].payor[0], element Bundle(https://fhir.kbv.de/StructureDefinition/KBV_PR_ERP_Bundle).entry.resource->Composition(https://fhir.kbv.de/StructureDefinition/KBV_PR_ERP_Composition).section.entry->MedicationRequest(https://fhir.kbv.de/StructureDefinition/KBV_PR_ERP_Prescription).insurance->Coverage(https://fhir.kbv.de/StructureDefinition/KBV_PR_FOR_Coverage).payor) 

This shouldn't have because identifier does not need to point to a contained reference. We don't need to resolve the identifier references at all.

[mmsmits]

This seems to be a side effect that the ref-1 invariant is acting up since we changed %rootResource, but this is not really trivial to find I guess.

[mmsmits]

My bad, this has been fixed in another PR