Refactoring Services (#61)

* Refactoring ViewModels into Razor Pages models

* Cleaning up Basket viewcomponent

* Refactoring services.
Fixed bug in basket item counter.

src/WebRazorPages/Services/CatalogService.cs

@@ -12,6 +12,10 @@ using System.Threading.Tasks;
 
 namespace Microsoft.eShopWeb.RazorPages.Services
 {
+    /// <summary>
+    /// This is a UI-specific service so belongs in UI project. It does not contain any business logic and works
+    /// with UI-specific types (view models and SelectListItem types).
+    /// </summary>
     public class CatalogService : ICatalogService
     {
         private readonly ILogger<CatalogService> _logger;