Add processor to show parents in hierarchical facets

I tested the patch on Facets 3.0, and it worked, but I had to make some changes. I had to implement the supportsFacet() method to work properly with facets_exposed_filters.
I’ll create a fork soon.

I assumed this new processor should only work with taxonomy terms, so I added the same check used in TermWeightWidgetOrderProcessor. To avoid duplicating code, I encapsulated the logic into a trait and updated that class to use it as well.

This is how it is rendered in filter settings.