Auth: Move access control API to SignedInUser interface (#73144)

* move access control api to SignedInUser interface

* remove unused code

* add logic for reading perms from a specific org

* move the specific org logic to org_user.go

* add a comment

---------

Co-authored-by: IevaVasiljeva <ieva.vasiljeva@grafana.com>

pkg/services/accesscontrol/mock/service_mock.go

@@ -6,7 +6,7 @@ import (
 	"github.com/stretchr/testify/mock"
 
 	"github.com/grafana/grafana/pkg/services/accesscontrol"
-	"github.com/grafana/grafana/pkg/services/user"
+	"github.com/grafana/grafana/pkg/services/auth/identity"
 )
 
 var _ accesscontrol.PermissionsService = new(MockPermissionsService)
@@ -19,7 +19,7 @@ type MockPermissionsService struct {
 	mock.Mock
 }
 
-func (m *MockPermissionsService) GetPermissions(ctx context.Context, user *user.SignedInUser, resourceID string) ([]accesscontrol.ResourcePermission, error) {
+func (m *MockPermissionsService) GetPermissions(ctx context.Context, user identity.Requester, resourceID string) ([]accesscontrol.ResourcePermission, error) {
 	mockedArgs := m.Called(ctx, user, resourceID)
 	return mockedArgs.Get(0).([]accesscontrol.ResourcePermission), mockedArgs.Error(1)
 }