Get the onnx file name of the trained network. This is the filename that your python script will save the onnx file to. On default this will return the following filename: "/YourModel/YourModel.onnx". Where "intermediatedir" is your project's Intermediate folder. And "YourModel" is the name of your runtime model class. So if you have a model class named UFancyModel, on default this method will return "/FancyModel/FancyModel.onnx"