Rename dco_get_peer_stats to dco_get_peer_stats_multi

Rename dco_get_peer_stats to dco_get_peer_stats_multi

Existing API and implementation (FreeBSD only) are designed for
server usage. Rename it to *_multi to indicate that and not to mix
with upcoming client API/implementation.

Signed-off-by: Lev Stipakov <lev@openvpn.net>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20221214132835.1010-1-lstipakov@gmail.com>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg25690.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>