Add back a date formatter guessing the century

NXP-7231 introduced changes to add century to default date formaters.
The problem is that it's not possible anymore to get a default date formater where century is guessed from current century, as the standard date format SHORT does.

=> add a new pseudo format "shortWithCentury" and make default formatters use it, and keep the "short" format as it was before changes done in NXP-7231.