Setting Cookie to IsEssential to fix anonymous signin

src/WebRazorPages/Pages/Basket/Index.cshtml.cs

@@ -84,7 +84,7 @@ namespace Microsoft.eShopWeb.RazorPages.Pages.Basket
             if (_username != null) return;
 
             _username = Guid.NewGuid().ToString();
-            var cookieOptions = new CookieOptions();
+            var cookieOptions = new CookieOptions { IsEssential = true };
             cookieOptions.Expires = DateTime.Today.AddYears(10);
             Response.Cookies.Append(Constants.BASKET_COOKIENAME, _username, cookieOptions);
         }