improve handling of data folder input

[elduvelle]

• could have an option to call it from the command line by 'dragging' the data folder as an argument: python -m run_tetrodes "Folder that I drag here"
• could have an option to select the data folder with the os explorer

[elduvelle]

Now doing it with 2 possible ways: write as an input to the code or give an empty folder input and select it by navigating to it instead