Importing score data from URL

[manoskary]

I propose to integrate the possibility to load scores from URLs such as github raw URLs, drive or others. This can make demos with Partitura easier as well as easier working with remote resources.
To do this I propose adding a small check on all import functions to check if the directory provided is a URL or local.
Then the following part of code should be integrated:

if is_url(path):
    data = load_data_from_url(path)
    lines = data.split("\n")
else:
    if not osp.exists(path):
        raise FileNotFoundError(f"File not found: {path}")
    with open(path, "r") as f:
        lines = f.readlines()
        assert validate_format(lines)