ForEach class

Iterates over the list elements and calls the provided function for each element. The function should take one argument: element.

var lst = [1, 2, 3];
lst.forEach(fun(element) {
    print(element);
});

Async example:
```js
var lst = [1, 2, 3];
lst.forEach(async fun(element) {
    await wait(1000);
    print(element);
});