private static V1Table loadV1Table(TableCatalog catalog, Identifier identifier)
      throws NoSuchTableException {
    Table table = catalog.loadTable(identifier);
    Preconditions.checkArgument(table instanceof V1Table, "source table must be V1Table");
    return (V1Table) table;
  }
migrate a v1 table to mixed-format table. will reuse file in v1 table , but delete metadata in
session catalog
amoro-format-mixed/amoro-mixed-spark/v3.3/amoro-mixed-spark-3.3/src/main/java/org/apache/amoro/spark/command/MigrateToMixedFormatCommand.java