fix: fixed A LOT of bugs and memory leaks. Removed ast_is_* commands as they're not really useful and seems redundant with ast_get_*. Also made some changes to lists utils to make architecture clearer and some other random tweaks or fixes.

src/utils/ast/ast_neg.h

@@ -9,7 +9,6 @@ struct ast_neg
     struct ast *child;
 };
 
-bool ast_is_neg(struct ast *node);
 struct ast_neg *ast_get_neg(struct ast *node);
 struct ast *ast_create_neg(bool negation, struct ast *child);
 void ast_free_neg(struct ast_neg *node);