String.IndexOf(value, caseSensitive) overload is missing

String.IndexOf(value) is case-insensitive by default, and related string search APIs allow callers to pass a Boolean caseSensitive argument without also passing a start index. String.IndexOf(value, caseSensitive) currently fails because the only two-argument overload expects startIndex As Integer. Users must write IndexOf(value, 0, caseSensitive) as a workaround.

Expected behaviour: IndexOf(value, True) should perform a case-sensitive search from index 0, while IndexOf(value, False) should preserve the current case-insensitive behaviour.