Can external reference resource be searched?
For example, let's say I have an Observation resource and the subject property has a value of 'http://external-fhir-service.org/some-url/Patient/123'. If a user does search with ?subject=http%3A%2F%2Fexternal-fhir-service.org%2Fsome-url%2FPatient%2F123, this should match.
However, if the user search for ?subject=Patient%2F123 or ?subject:Patient=123, should this also match? From my service, I have no context of what the base URL of that external service is.