On the tracks I tested the server number in the url from the webpage is valid
for the mp3 or the m4a file and any other number is invalid, it's a
waste of time to check them.
· Import from compat what comes from compat. Yes, some names are available in utils too, but that's an implementation detail.
· Use _match_id consistently whenever possible
· Fix some outdated tests
· Use consistent valid URL (always match the whole protocol, no ^ at start required)
· Use modern test definitions