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

Add tests for files from the future
I'm not sure about you but I find this easier to read (with some comments about what these return values mean):

```cs
dynSettings.Controller.OnRequestTaskDialog(null, args);
if (args.ClickedButtonId == 43421) {
    dynSettings.Controller.DownloadDynamo();
    return false; // Do not proceed to open file.
}

// Proceed only if user chooses to
return (args.ClickedButtonId == 43422)
```