AuthN: Implement requester interface for identity (#75618)

* AuthN: Implement identity.Requester interface for authn.Identity

* AuthN: Replace OrgRole with GetOrgRole

* IDForwarding: skip converting to SignedInUser

* Pass identity directly in permission sync hook

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

@@ -30,8 +30,7 @@ func (s *PermissionsSync) SyncPermissionsHook(ctx context.Context, identity *aut
 		return nil
 	}
 
-	permissions, err := s.ac.GetUserPermissions(ctx, identity.SignedInUser(),
-		accesscontrol.Options{ReloadCache: false})
+	permissions, err := s.ac.GetUserPermissions(ctx, identity, accesscontrol.Options{ReloadCache: false})
 	if err != nil {
 		s.log.FromContext(ctx).Error("Failed to fetch permissions from db", "error", err, "user_id", identity.ID)
 		return errSyncPermissionsForbidden