Casting List to String Ignores Format Options

[tustvold]

Describe the bug

To Reproduce

#[test]
    fn test_list_format_options() {
        let options = CastOptions {
            safe: false,
            format_options: FormatOptions::default().with_null("null"),
        };
        let array = ListArray::from_iter_primitive::<Int32Type, _, _>(vec![
            Some(vec![Some(0), Some(1), Some(2)]),
            Some(vec![Some(0), None, Some(2)]),
        ]);
        let a = cast_with_options(&array, &DataType::Utf8, &options).unwrap();
        let r: Vec<_> = a.as_string::<i32>().iter().map(|x| x.unwrap()).collect();
        assert_eq!(r, &["[0, 1, 2]", "[0, null, 2]"]);
    }

Expected behavior

Additional context

[tustvold]

label_issue.py automatically added labels {'arrow'} from #4668