remove empty lists as default arguments in functions

Let me sketch the problem: Using [] as default argument will only be evaluated once for each function. This is why all function calls will use the same list which is usually not intended. For more details, see e.g. https://nikos7am.com/posts/mutable-default-arguments/

Hey all! I would like to work on this. I used ripgrep to find any default list arguments. Will test it today and make a PR.