Remove Configurator interface

The Configurator has been used as a holder for listers that tests need,
which is not its purpose. By making the tests obtain listers from more
appropriate places, such as informers, there is no need for various
accessors to the Configurator.

Also, FakeConfigurator is not being used anymore, so there's no need for
an interface instead of a plain pointer.

Signed-off-by: Aldo Culquicondor <acondor@google.com>

pkg/scheduler/api/compatibility/compatibility_test.go

@@ -1097,7 +1097,6 @@ func TestCompatibility_v1_Scheduler(t *testing.T) {
 		informerFactory := informers.NewSharedInformerFactory(client, 0)
 
 		if _, err := factory.NewConfigFactory(&factory.ConfigFactoryArgs{
-			SchedulerName:                  "some-scheduler-name",
 			Client:                         client,
 			NodeInformer:                   informerFactory.Core().V1().Nodes(),
 			PodInformer:                    informerFactory.Core().V1().Pods(),