cmdlist: use new architecture (STUB)

I fixed the tests, and the basic functionallity of detecting pipelines works,
but detecting nested cmdgroups is not yet implemented

NOTES.md

@@ -208,22 +208,22 @@ not remain in effect after the subshell completes.
 The exit status of this construct is the exit status of LIST.
 
 ```c
-typedef enum e_cmdgroup_item_type
+typedef enum e_cmdlist_item_type
 {
    TYPE_INVALID,
    TYPE_CMDGROUP,
    TYPE_PIPELINE,
-}  t_cmdgroup_item_type;
+}  t_cmdlist_item_type;
 
 typedef struct s_cmdlist_item
 {
-	enum e_cmdgroup_item_type	type;
-	union u_cmdgroup_item_inner
+	enum e_cmdlist_item_type	type;
+	union u_cmdlist_item_inner
 	{
 		t_cmdgroup			*cmdgroup;
       struct s_pipeline *pipeline;
 	}	inner;
-}	t_cmdgroup_item;
+}	t_cmdlist_item;
 
 typedef s_cmdlist
 {