Removing IRepository

- This also involved cleaning up places where IRepository was still being references in Startup
- Removed unused repository from Basket service

src/ApplicationCore/Interfaces/IRepository.cs

@@ -1,10 +0,0 @@
-using Microsoft.eShopWeb.ApplicationCore.Entities;
-using System.Collections.Generic;
-
-namespace Microsoft.eShopWeb.ApplicationCore.Interfaces
-{
-    public interface IRepository<T> where T : BaseEntity
-    {
-        
-    }
-}