Response to denyAccess causes exception

Describe the bug

If you call denyAccess the response from the VC service includes the type vc:SolidAccessDenial. This is not in the allowed types so this fails. It expects either the localname or the fully qualified name. If the response was processed as RDF it would not be an issue but it is processed as JSON.

Expected behavior

Return the access credential.

Actual behavior

Throws AccessGrantException("Invalid Access Grant: missing supported type")

How to reproduce?

An end to end test should show this problem. Tests using mocking repeat the same assumptions about the types used so do not detect the fault.

Output of java -version

No response

Maven version

No response

Additional information

It seems odd that the VC service treats SolidAccessDenial differently to SolidAccessGrant - it would be better if they were both defined in the VC context and then this library would have worked.