This function copies the test data from the R package to a user-defined folder. This is necesarry since the model does not read the data from R.
The model needs to be run in a seperate folder and the executable can be downloaded from the provided URL. The executable needs to be copied to the folder where the data is located. The folder structure should be maintained.
If the specified folder does not exist, the function will create it at the user defined loaction. If the packages are installed on default path, then the package_folder argument can be kept empty. If not, the user has to provide the path where the R package is installed.