Adds copyright for some new files

Author: alex-kulakov

Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperGetGenericInterfaceTests.cs

@@ -1,3 +1,7 @@
+// Copyright (C) 2020 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
+
 using System;
 using System.Collections.Generic;
 using NUnit.Framework;

Orm/Xtensive.Orm.Tests.Core/Reflection/TypeHelperGetGenericTypeTests.cs

@@ -1,3 +1,7 @@
+// Copyright (C) 2020 Xtensive LLC.
+// This code is distributed under MIT license terms.
+// See the License.txt file in the project root for more information.
+
 using System;
 using System.Collections.Generic;
 using NUnit.Framework;