Add support for Twig extra packages

[stof]

For Twig 2+, it would be great to provide the extensions available in twig/*-extra packages (I just tried using some filter from twig/intl-extra).

[stof]

@ninsuo is this something planned ?

[ninsuo]

Hello @stof

I may have a look yes, sorry I was a bit busy those last months.

I'll check that.
Cheers

[alexander-schranz]

Would really like to see them in the twigfiddle :)