OAuth: Use the attached external session data in OAuthToken and OAuthTokenSync (#96655)

* wip

* wip + tests

* wip

* wip opt2

* Use authn.Identity struct's SessionToken

* Merge fixes

* Handle disabling the feature flag correctly

* Fix test

* Cleanup

* Remove HasOAuthEntry from the OAuthTokenService interface

* Remove unused function

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

@@ -20,6 +20,9 @@ import (
 	"github.com/grafana/grafana/pkg/services/auth"
 	"github.com/grafana/grafana/pkg/services/auth/authtest"
 	"github.com/grafana/grafana/pkg/services/authn"
+	"github.com/grafana/grafana/pkg/services/contexthandler/ctxkey"
+	contextmodel "github.com/grafana/grafana/pkg/services/contexthandler/model"
+	"github.com/grafana/grafana/pkg/services/featuremgmt"
 	"github.com/grafana/grafana/pkg/services/login"
 	"github.com/grafana/grafana/pkg/services/oauthtoken/oauthtokentest"
 )
@@ -85,7 +88,7 @@ func TestOAuthTokenSync_SyncOAuthTokenHook(t *testing.T) {
 			)
 
 			service := &oauthtokentest.MockOauthTokenService{
-				TryTokenRefreshFunc: func(ctx context.Context, usr identity.Requester) (*oauth2.Token, error) {
+				TryTokenRefreshFunc: func(ctx context.Context, usr identity.Requester, _ *auth.UserToken) (*oauth2.Token, error) {
 					tryRefreshCalled = true
 					return nil, tt.expectedTryRefreshErr
 				},
@@ -116,9 +119,13 @@ func TestOAuthTokenSync_SyncOAuthTokenHook(t *testing.T) {
 				singleflightGroup: new(singleflight.Group),
 				tracer:            tracing.InitializeTracerForTest(),
 				cache:             localcache.New(maxOAuthTokenCacheTTL, 15*time.Minute),
+				features:          featuremgmt.WithFeatures(),
 			}
 
-			err := sync.SyncOauthTokenHook(context.Background(), tt.identity, nil)
+			ctx := context.Background()
+			reqCtx := context.WithValue(ctx, ctxkey.Key{}, &contextmodel.ReqContext{UserToken: nil})
+
+			err := sync.SyncOauthTokenHook(reqCtx, tt.identity, nil)
 			assert.ErrorIs(t, err, tt.expectedErr)
 			assert.Equal(t, tt.expectTryRefreshTokenCalled, tryRefreshCalled)
 			assert.Equal(t, tt.expectRevokeTokenCalled, revokeTokenCalled)