Conceptually in TLSv1.3 there can be multiple sessions associated with a
single connection. Each NewSessionTicket issued can be considered a
separate session. We can end up issuing multiple NewSessionTickets on a
single connection at the moment (e.g. in a post-handshake auth scenario).
Each of those issued tickets should have the new_session_cb called, it
should go into the session cache separately and it should have a unique
id associated with it (so that they can be found individually in the
cache).
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5644)