Session: set authID and authenticatedBy (#85806)

* Authn: Resolve authenticate by and auth id when fethcing signed in user

* Change logout client interface to only take Requester interface

* Session: Fetch external auth info when authenticating sessions

* Use authenticated by from identity

* Move call to get auth-info into session client and use GetAuthenticatedBy in various places

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

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"strconv"
 
 	"github.com/grafana/grafana/pkg/infra/log"
 	authidentity "github.com/grafana/grafana/pkg/services/auth/identity"
@@ -110,12 +111,13 @@ func (s *UserSync) FetchSyncedUserHook(ctx context.Context, identity *authn.Iden
 	if !identity.ClientParams.FetchSyncedUser {
 		return nil
 	}
+
 	namespace, id := identity.GetNamespacedID()
-	if namespace != authn.NamespaceUser && namespace != authn.NamespaceServiceAccount {
+	if !authidentity.IsNamespace(namespace, authn.NamespaceUser, authn.NamespaceServiceAccount) {
 		return nil
 	}
 
-	userID, err := authidentity.IntIdentifier(namespace, id)
+	userID, err := strconv.ParseInt(id, 10, 64)
 	if err != nil {
 		s.log.FromContext(ctx).Warn("got invalid identity ID", "id", id, "err", err)
 		return nil