Rolling back change to use extension method to wiret up config

- The change is a better way to do the configuration, but there is
currently an issue where the Value Objects are not being honored and
being treated like Entitys. When this happens, the container will throw
errors when trying to start up because the entitys are lacking primary
keys (when they don't need them).

src/ApplicationCore/Entities/OrderAggregate/Address.cs

@@ -3,7 +3,6 @@ using System;
 
 namespace Microsoft.eShopWeb.ApplicationCore.Entities.OrderAggregate
 {
-    [Owned]
     public class Address // ValueObject
     {
         public String Street { get; private set; }

src/ApplicationCore/Entities/OrderAggregate/CatalogItemOrdered.cs

@@ -7,7 +7,6 @@ namespace Microsoft.eShopWeb.ApplicationCore.Entities.OrderAggregate
     /// Represents a snapshot of the item that was ordered. If catalog item details change, details of
     /// the item that was part of a completed order should not change.
     /// </summary>
-    [Owned]
     public class CatalogItemOrdered // ValueObject
     {
         public CatalogItemOrdered(int catalogItemId, string productName, string pictureUri)