Support RFC 9493 ("sub_id" claim) #16907
Description
Expected Behavior
RFC 9493 defines the "sub_id" claim for transmitting typed subject identifiers, rather than relying on the flat string of "sub".
Support for this at the Resource and Authroization servers would be very helpful, similar to the SAML ID support.
Current Behavior
Manually parsing and serialising the structures and string constants from/to the Map<String, Object> of claims.
Context
Identifying users that may have multiple identifiers, federating across domains that may have identifier conflicts, etc.