Basket : Improve, reduce, remove duplication call to database (#610)

src/ApplicationCore/Interfaces/IBasketService.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using Microsoft.eShopWeb.ApplicationCore.Entities.BasketAggregate;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 
 namespace Microsoft.eShopWeb.ApplicationCore.Interfaces
@@ -6,8 +7,8 @@ namespace Microsoft.eShopWeb.ApplicationCore.Interfaces
     public interface IBasketService
     {
         Task TransferBasketAsync(string anonymousId, string userName);
-        Task AddItemToBasket(int basketId, int catalogItemId, decimal price, int quantity = 1);
-        Task SetQuantities(int basketId, Dictionary<string, int> quantities);
+        Task<Basket> AddItemToBasket(string username, int catalogItemId, decimal price, int quantity = 1);
+        Task<Basket> SetQuantities(int basketId, Dictionary<string, int> quantities);
         Task DeleteBasketAsync(int basketId);
     }
 }