Add support for updated member-match operation

**User story**
As a user, I want to be able to use the $member-match operations in FHIR as defined in the updated HRex implemenation: https://build.fhir.org/ig/HL7/davinci-ehrx/OperationDefinition-member-match.html

**Acceptance criteria**
I can use the $member-match with consent

Start by reading the linked HRex OperationDefinition for the updated $member-match operation and compare its requirements with the server's current behavior. Trace the existing $member-match entry point and related consent handling; done means a member-match request with consent works according to the updated specification.

Written by the indexing model from the issue text.