[release-10.4.18] Auth: Fix SAML user IsExternallySynced not being set correctly (#98487) (#103177)

* Auth: Fix SAML user IsExternallySynced not being set correctly (#98487)

(cherry picked from commit 345757c3ae)

* Test fixes

* lint

---------

Co-authored-by: xavi <114113189+volcanonoodle@users.noreply.github.com>

pkg/api/utils.go

@@ -1,10 +1,14 @@
 package api
 
 import (
+	"context"
+	"errors"
 	"net/mail"
 
 	"github.com/grafana/grafana/pkg/middleware/cookies"
 	contextmodel "github.com/grafana/grafana/pkg/services/contexthandler/model"
+	"github.com/grafana/grafana/pkg/services/login"
+	"github.com/grafana/grafana/pkg/services/user"
 )
 
 func (hs *HTTPServer) GetRedirectURL(c *contextmodel.ReqContext) string {
@@ -20,6 +24,20 @@ func (hs *HTTPServer) GetRedirectURL(c *contextmodel.ReqContext) string {
 	return redirectURL
 }
 
+func (hs *HTTPServer) isExternalUser(ctx context.Context, userID int64) (bool, error) {
+	getAuthQuery := login.GetAuthInfoQuery{UserId: userID}
+	var err error
+	if _, err = hs.authInfoService.GetAuthInfo(ctx, &getAuthQuery); err == nil {
+		return true, nil
+	}
+
+	if errors.Is(err, user.ErrUserNotFound) {
+		return false, nil
+	}
+
+	return false, err
+}
+
 func ValidateAndNormalizeEmail(email string) (string, error) {
 	if email == "" {
 		return "", nil