MINOR: listener: Add QUIC info to listeners and receivers.

This patch adds a quic_transport_params struct to bind_conf struct
used for the listeners. This is to store the QUIC transport parameters
for the listeners. Also initializes them when calling str2listener().
Before str2sa_range() it's too early to figure we're going to speak QUIC,
and after it's too late as listeners are already created. So it seems that
doing it in str2listener() when the protocol is discovered is the best
place.

Also adds two ebtrees to the underlying receivers to store the connection
by connections IDs (one for the original connection IDs, and another
one for the definitive connection IDs which really identify the connections.

However it doesn't seem normal that it is stored in the receiver nor the
listener. There should be a private context in the listener so that
protocols can store internal information. This element should in
fact be the listener handle.

Something still feels wrong, and probably we'll have to make QUIC and
SSL co-exist: a proof of this is that there's some explicit code in
bind_parse_ssl() to prevent the "ssl" keyword from replacing the xprt.
diff --git a/src/proto_quic.c b/src/proto_quic.c
index 751fc49..8b3e91b 100644
--- a/src/proto_quic.c
+++ b/src/proto_quic.c
@@ -46,6 +46,7 @@
 #include <haproxy/tools.h>
 
 
+static void quic_add_listener(struct protocol *proto, struct listener *listener);
 static int quic_bind_listener(struct listener *listener, char *errmsg, int errlen);
 static int quic_connect_server(struct connection *conn, int flags);
 static void quic_enable_listener(struct listener *listener);
@@ -60,7 +61,7 @@
 	.listen         = quic_bind_listener,
 	.enable         = quic_enable_listener,
 	.disable        = quic_disable_listener,
-	.add            = default_add_listener,
+	.add            = quic_add_listener,
 	.unbind         = default_unbind_listener,
 	.suspend        = default_suspend_listener,
 	.resume         = default_resume_listener,
@@ -97,7 +98,7 @@
 	.listen         = quic_bind_listener,
 	.enable         = quic_enable_listener,
 	.disable        = quic_disable_listener,
-	.add            = default_add_listener,
+	.add            = quic_add_listener,
 	.unbind         = default_unbind_listener,
 	.suspend        = default_suspend_listener,
 	.resume         = default_resume_listener,
@@ -513,6 +514,18 @@
 	return SF_ERR_NONE;  /* connection is OK */
 }
 
+/* Add listener <listener> to protocol <proto>. Technically speaking we just
+ * initialize a few entries which should be doable during quic_bind_listener().
+ * The end of the initialization goes on with the default function.
+ */
+static void quic_add_listener(struct protocol *proto, struct listener *listener)
+{
+	LIST_INIT(&listener->rx.qpkts);
+	listener->rx.odcids = EB_ROOT_UNIQUE;
+	listener->rx.cids = EB_ROOT_UNIQUE;
+	default_add_listener(proto, listener);
+}
+
 /* This function tries to bind a QUIC4/6 listener. It may return a warning or
  * an error message in <errmsg> if the message is at most <errlen> bytes long
  * (including '\0'). Note that <errmsg> may be NULL if <errlen> is also zero.