Distinguish outdated schema from invalid schema in repl apply (#6710)

Author: Enjection

ydb/core/protos/tx_datashard.proto

@@ -1829,6 +1829,7 @@ message TEvApplyReplicationChangesResult {
         REASON_SCHEME_ERROR = 2;
         REASON_BAD_REQUEST = 3;
         REASON_UNEXPECTED_ROW_OPERATION = 4;
+        REASON_OUTDATED_SCHEME = 6;
     }
 
     optional EStatus Status = 1;

ydb/core/tx/datashard/datashard_repl_apply.cpp

@@ -65,7 +65,9 @@ class TDataShard::TTxApplyReplicationChanges : public TTransactionBase<TDataShar
                 << " and cannot apply changes for schema version " << tableId.GetSchemaVersion();
             Result = MakeHolder<TEvDataShard::TEvApplyReplicationChangesResult>(
                 NKikimrTxDataShard::TEvApplyReplicationChangesResult::STATUS_REJECTED,
-                NKikimrTxDataShard::TEvApplyReplicationChangesResult::REASON_SCHEME_ERROR,
+                tableId.GetSchemaVersion() < userTable.GetTableSchemaVersion()
+                    ? NKikimrTxDataShard::TEvApplyReplicationChangesResult::REASON_OUTDATED_SCHEME
+                    : NKikimrTxDataShard::TEvApplyReplicationChangesResult::REASON_SCHEME_ERROR,
                 std::move(error));
             return true;
         }