fix the CatalogRepository in [Use an Aggregate with Double Dispatch] and its unit testing

[u8989332]

Hi When I run all testing in solution, I find the ProductUpdateNameTests of NoDuplicatesDesigns._08_AggregateWithDoubleDispatch can't pass UpdatesNameGivenNewUniqueName/ThrowsExceptionGivenDuplicateName testing.

The reason is CatalogRepository didn't create correct Product instances because of lost CatalogId.

Please review the modification, thanks.