It can be useful in the UIs of AuthorizationStrategies to allow the user to see the members of the groups defined external to Jenkins (i.e. defined in the backing SecurityRealm)

It is likely that not every security realm will support this operation, but certainly realms such as ActiveDirectory and LDAP should be able to support retrieving this information, so we should provide an API that permits these realms to provide this extra information so that AuthorizationStrategies can enhance the UX