Add project files.

ConstructorApp.DataAccessLayer/Abstract/IGenericDal.cs

@@ -0,0 +1,12 @@
+namespace ConstructorApp.DataAccessLayer.Abstract
+{
+    public interface IGenericDal<T> where T : class
+    {
+        void Add(T entity);
+        void Delete(T entity);
+        void Update(T entity);
+        T GetByID(int id);
+        List<T> GetListAll();
+        Task<List<T>> GetListAllAsync();
+    }
+}