Use PHP DateInputWidget in Contribs and use for range filtering

Use PHP DateInputWidget in Contribs and use for range filtering

* Add two DateInputWidgets to Special:Contributions, one for start and
  one for end
** If start input is empty but end input is not, display edits up to end
   input, and vice versa
** If both inputs are specified, display edits between the two dates
** If both inputs are empty, no date range is used
* Legacy options (year=/month=) are converted to use for the end
  timestamp, so URLs with them should still work.
* Unit tests!

Bug: T120733
Change-Id: Id15f2b2ce2954fe98dfbbb7b0e86c0e4e5713f5e