[openssl/openssl] 3b8669: augment quic demos to support ipv4/6 connections

[Neil Horman]

  Branch: refs/heads/openssl-3.2
  Home:   https://github.com/openssl/openssl
  Commit: 3b866985ba8a85b85034eb01d6ad286db678bb13
      https://github.com/openssl/openssl/commit/3b866985ba8a85b85034eb01d6ad286db678bb13
  Author: Neil Horman <nhorman at openssl.org>
  Date:   2023-11-21 (Tue, 21 Nov 2023)

  Changed paths:
    M demos/guide/quic-client-block.c
    M demos/guide/quic-client-non-block.c
    M demos/guide/quic-multi-stream.c
    M demos/guide/tls-client-block.c
    M demos/guide/tls-client-non-block.c
    M doc/man7/ossl-guide-quic-client-block.pod
    M doc/man7/ossl-guide-tls-client-block.pod

  Log Message:
  -----------
  augment quic demos to support ipv4/6 connections

Because the quicserver utility supports expressly listening in ipv4/6
mode, its possible/likely that the server will listen on an ipv4
address, while the clients will connect via ipv6, leading to connection
failures.

Augment quic demo clients to afford them the same -6 option that the
server has so that connection family can be co-ordinated

Reviewed-by: Nicola Tuveri <nic.tuv at gmail.com>
Reviewed-by: Hugo Landau <hlandau at openssl.org>
Reviewed-by: Matt Caswell <matt at openssl.org>
Reviewed-by: Richard Levitte <levitte at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/22577)

(cherry picked from commit 5091aadc223315ce115ee12f62df2af173bf5efb)