Date range - honour dependent facets

Problem/Motivation

The Date range facet does not go away when the dependent processor's conditions are not met.

Steps to reproduce

- two facets, "parent" and "dependent"
- set the "dependent" to appear on a certain value of the "parent"
- go to the view page (or whatever page uses the index)
- you should not see the dependent date range facet, but you do.

Proposed resolution

Add a check in the widget itself to check to processors again, this is done by the DefaultFacetManager BUT, that only empties the results, which is not compatible with our Date Range widget, so we need to re-check and use a bool as result.