Make the path handling OS-independent in benchmetrics.py

[sara-mft]

In benchmetrics.py, adapt line 86 to be flexible with different operating systems by using os.path methods:

• DATA_NAME = path.split("/")[-1].split(".")[0].replace("\\", "_") ==> DATA_NAME = os.path.splitext(os.path.basename(path))[0].replace("\\", "_")