[Validator] Support validating codes against ValueSets contained in StructureDefinitions

[mmsmits]

Describe the bug
The validator should support validating codes against ValueSets contained in StructureDefinitions. There is a use case where StructureDefinitions define bindings to valuesets that are contained (referenced with a #) in that SD itself . The validator currently doesn't resolve those ValueSets and therefor can't validate codes against them.

To Reproduce
Run the RunSingleTest() test method in ValidationManifestTest.cs using patient-translated-codes in the R4 branch.

Expected behavior
The validator should be able to resolve the contained valuesets (maybe with a new ResourceResolver, like an "InstanceResolver"), and should be able to contain codes against them.

Version used:

• FHIR Version: STU3, R4, R5

Additional context
This issue/feature has come to light comparing the Java Validator against the .NET validator.

[ewoutkramer]

Duplicate of FirelyTeam/firely-net-sdk#1747. This needs general support from the SDK, as defined in the referred issue. Closing this issue.