Добавил интерфейсы моделей данных

InternetShop/InternetShopDataModels/IId.cs

@@ -0,0 +1,7 @@
+namespace InternetShopDataModels
+{
+    public interface IId
+    {
+        int Id { get; }
+    }
+}

InternetShop/InternetShopDataModels/Models/IOrderModel.cs

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+namespace InternetShopDataModels.Models
+{
+    public interface IOrderModel : IId
+    {
+        string CustomerFIO { get; }
+        string CustomerEmail { get; }
+        string ImagePath { get; }
+        List<IProductModel> Products { get; }
+    }
+}

InternetShop/InternetShopDataModels/Models/IProductModel.cs

@@ -0,0 +1,7 @@
+namespace InternetShopDataModels.Models
+{
+    public interface IProductModel : IId
+    {
+        string Name { get; }
+    }
+}