Add resource_class for DiscoveredHostsController

Fix error on Discovered host detail page:

unable to detect breadcrumb title name in for discovered_hosts, defaulting to name
<NameError> Could not find resource class for resource discovered_host

app/controllers/discovered_hosts_controller.rb

@@ -198,6 +198,10 @@ def submit_multiple_auto_provision
     end
   end
 
+  def resource_class
+    Host::Discovered
+  end
+
   private
 
   def setup_host_class_variables