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

Np re: questions :).

You can only use something like ```engine.send("auto_complete_path")``` for resources and paths that Rails is aware of. You'll need to write a custom mapper for angular...

The example you used should return ```'auto_complete_search'```?

Something like this should do the trick: 
```
search_path_override("Katello") do |resource|
  case resource
    when 'Katello::Content_View'
      '/katello/content_views/auto_complete_path'
    else
      "katello/#{resource.deconstantise.pluralise}/another_search_path"
  end
end
```