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/addons/51degrees/51d.c b/addons/51degrees/51d.c
index 2c52c59..6dfa578 100644
--- a/addons/51degrees/51d.c
+++ b/addons/51degrees/51d.c
@@ -91,7 +91,7 @@
 	while (*(args[cur_arg])) {
 		name = calloc(1, sizeof(*name));
 		name->name = strdup(args[cur_arg]);
-		LIST_ADDQ(&global_51degrees.property_names, &name->list);
+		LIST_APPEND(&global_51degrees.property_names, &name->list);
 		++cur_arg;
 	}
 
@@ -730,7 +730,7 @@
 
 	ha_free(&global_51degrees.data_file_path);
 	list_for_each_entry_safe(_51d_prop_name, _51d_prop_nameb, &global_51degrees.property_names, list) {
-		LIST_DEL(&_51d_prop_name->list);
+		LIST_DELETE(&_51d_prop_name->list);
 		free(_51d_prop_name);
 	}