Auth: Use authn.Service for all tests (#72921)

* Dashboards: Fix tests when authn broker is enabled.
StarService was not configured for tests, the call was guarded by !c.IsSignedIn

* Change default to be anon user to match expectations from tests

* OAuth: rewrite tests to work with authn.Service

* Setup template renderer by default

* Extract cookie options from cfg instead of relying on global variables

* Fix test to work with authn service

* Middleware: rewrite auth tests

* Remvoe session cookie if we cannot refresh access token

pkg/services/authn/authnimpl/sync/oauth_token_sync_test.go

@@ -89,7 +89,7 @@ func TestOAuthTokenSync_SyncOAuthTokenHook(t *testing.T) {
 			expectInvalidateOauthTokensCalled: true,
 			expectRevokeTokenCalled:           true,
 			expectedHasEntryToken:             &login.UserAuth{OAuthExpiry: time.Now().Add(-10 * time.Minute)},
-			expectedErr:                       errExpiredAccessToken,
+			expectedErr:                       authn.ErrExpiredAccessToken,
 		}, {
 			desc:                        "should skip sync when use_refresh_token is disabled",
 			identity:                    &authn.Identity{ID: "user:1", SessionToken: &auth.UserToken{}, AuthenticatedBy: login.GitLabAuthModule},