[formatsort] Remove misuse of 'preference'

'preference' is to be used only when the format is better that ALL qualities of a lower preference irrespective of ANY sorting order the user requests. See deezer.py for correct use of this

In the older sorting method, `preference`, `quality` and `language_preference` were functionally almost equivalent. So these disparities doesn't really matter there

Also, despite what the documentation says, the default for `preference` was actually 0 and not -1. I have tried to correct this and also account for it when converting `preference` to `quality`

youtube_dlc/extractor/espn.py

@@ -154,7 +154,7 @@ class ESPNIE(OnceIE):
                         'tbr': int(mobj.group(3)),
                     })
                 if source_id == 'mezzanine':
-                    f['preference'] = 1
+                    f['quality'] = 1
                 formats.append(f)
 
         links = clip.get('links', {})