add date_formats parameter to DateDataParser

[brl0]

Splitting out from my comment in #939 :

from what I could tell, the DateDataParser does not accept a date_formats parameter, even in the settings dictionary, instead it looks like that must be passed through to the method called to parse the string, which seemed a bit unintuitive to me.

And here was the response from @noviluni:

Yeah, that's weird. In fact, the date_format is applied twice, before translating/cleaning and after if I remember correctly. Feel free to open a new issue and submit a PR with this change, it could be nice to have it :)