RBAC: Clean up action set code (#88147)

* remove unused action set code, refactor the existing code

* fix import ordering

* use a separate interface for permission expansion after all, to avoid circular dependencies

* add comments, fix a test

pkg/services/accesscontrol/acimpl/accesscontrol.go

@@ -48,10 +48,6 @@ func (a *AccessControl) Evaluate(ctx context.Context, user identity.Requester, e
 		return false, nil
 	}
 
-	if a.features.IsEnabled(ctx, featuremgmt.FlagAccessActionSets) {
-		evaluator = evaluator.AppendActionSets(ctx, a.resolvers.GetActionSetResolver())
-	}
-
 	a.debug(ctx, user, "Evaluating permissions", evaluator)
 	// Test evaluation without scope resolver first, this will prevent 403 for wildcard scopes when resource does not exist
 	if evaluator.Evaluate(permissions) {
@@ -74,10 +70,6 @@ func (a *AccessControl) RegisterScopeAttributeResolver(prefix string, resolver a
 	a.resolvers.AddScopeAttributeResolver(prefix, resolver)
 }
 
-func (a *AccessControl) RegisterActionResolver(resolver accesscontrol.ActionResolver) {
-	a.resolvers.SetActionResolver(resolver)
-}
-
 func (a *AccessControl) debug(ctx context.Context, ident identity.Requester, msg string, eval accesscontrol.Evaluator) {
 	namespace, id := ident.GetNamespacedID()
 	a.log.FromContext(ctx).Debug(msg, "namespace", namespace, "id", id, "orgID", ident.GetOrgID(), "permissions", eval.GoString())