fixes #5753: Engines can now override autocomplete path used in FiltersHelper

How should I be getting the Foreman-style URL's for Katello then?  

FiltersHelper resource_path doesn't work for Katello (engine.send("content_views_path") returns nil, I assume because of the Angular routing).

If I use the new overrides -- `search_path_override "Katello" { "auto_complete_search" }` it generates /filters/auto_complete_search, but I want it do it for the target resource (e.g. /content_views/auto_complete_search) like it does for Foreman filters.

> Having said that, I just added support for passing in resource name in the override block. I still think it's a good idea to stick to foreman's format of urls in general, but I realize that you may need to sometimes tailor search paths to specific models... 

How? All I see is the tests and method comment changed to mention |resource|.

Sorry for all the questions, I'm still trying to wrap my head around all of this.