Issue/12227 formatDate() improvements

* Add support for giving L10N
* Add support for $options from `$l->l()` to `formatDate()`
* Add support for relative dates (can be done with above step, as Punic\Calendar just requires adding a ^ to the format string)

Fixes #12227 

@DeepDiver1975 @PVince81 @MorrisJobke 
I have to agree with @LukasReschke - this is fishy - I'm on the road these days - let me have a look at this until the end of this week. THX