CLEANUP: lists/tree-wide: rename some list operations to avoid some confusion

The current "ADD" vs "ADDQ" is confusing because when thinking in terms
of appending at the end of a list, "ADD" naturally comes to mind, but
here it does the opposite, it inserts. Several times already it's been
incorrectly used where ADDQ was expected, the latest of which was a
fortunate accident explained in 6fa922562 ("CLEANUP: stream: explain
why we queue the stream at the head of the server list").

Let's use more explicit (but slightly longer) names now:

   LIST_ADD        ->       LIST_INSERT
   LIST_ADDQ       ->       LIST_APPEND
   LIST_ADDED      ->       LIST_INLIST
   LIST_DEL        ->       LIST_DELETE

The same is true for MT_LISTs, including their "TRY" variant.
LIST_DEL_INIT keeps its short name to encourage to use it instead of the
lazier LIST_DELETE which is often less safe.

The change is large (~674 non-comment entries) but is mechanical enough
to remain safe. No permutation was performed, so any out-of-tree code
can easily map older names to new ones.

The list doc was updated.
diff --git a/src/protocol.c b/src/protocol.c
index cd574f2..767e03a 100644
--- a/src/protocol.c
+++ b/src/protocol.c
@@ -36,7 +36,7 @@
 void protocol_register(struct protocol *proto)
 {
 	HA_SPIN_LOCK(PROTO_LOCK, &proto_lock);
-	LIST_ADDQ(&protocols, &proto->list);
+	LIST_APPEND(&protocols, &proto->list);
 	if (proto->fam->sock_domain >= 0 && proto->fam->sock_domain < AF_CUST_MAX)
 		__protocol_by_family[proto->fam->sock_domain]
 			[proto->sock_type == SOCK_DGRAM]
@@ -50,7 +50,7 @@
 void protocol_unregister(struct protocol *proto)
 {
 	HA_SPIN_LOCK(PROTO_LOCK, &proto_lock);
-	LIST_DEL(&proto->list);
+	LIST_DELETE(&proto->list);
 	LIST_INIT(&proto->list);
 	HA_SPIN_UNLOCK(PROTO_LOCK, &proto_lock);
 }