DNM: Defect fix: MAGN-1380 - Add tests for files from the future

Add tests for files from the future
I'd prefer a non-UI test (i.e. put it in DynamoCoreTests.dll) if possible. In which case there is no ```View```, and the ultimate request to show task dialog will be a no-op. That means ```TaskDialogEventArgs.ClickedButtonId``` will be left as ```0``` and the handler (i.e. Aparajit's code) should properly handle that case.