Format Widget for long strings

a format widget would be useful to display long strings in a human readable form (max group of 4 characters)
the idea is to specify a format mask which is used to display long strings and to revert strings with formatting characters to strings without spaces or separators
Examples are
IBAN "AT53 1920 0085 7759 6007" instead of "AT531920008577596007"
EAN "90 123 451 234 5" instead of "901234512345"
ISBN
tel numbers "+43-1-712 21 90-12" instead of "+431712219012" (needs various formatting rules!)