Improve test coverage of rbac stuff

Description

Trying to improve coverage. 🥴

Related Issue

#207 (closed)

controller/northbound/server/auth_interceptor.go

@@ -125,16 +125,23 @@ func (auth *AuthInterceptor) verifyUserRoleAndRequestedCall(userRole, requestedM
 		return err
 	}
 
+	foundRoleInStorage := false
+
 	for _, storedRole := range storedRoles {
 		if userRole == storedRole.Name() {
+			foundRoleInStorage = true
 			err := auth.compareRequestedPermissionWithRolePermissions(requestedMethod, storedRole.GetPermissions())
 			if err != nil {
 				return err
 			}
 		}
+
+		if foundRoleInStorage {
+			return nil
+		}
 	}
 
-	return nil
+	return status.Errorf(codes.PermissionDenied, "wrong permissions")
 }
 
 func (auth *AuthInterceptor) compareRequestedPermissionWithRolePermissions(requestedMethod string, storedRolePermissions []string) error {