[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/canalplus.py

@@ -89,7 +89,7 @@ class CanalplusIE(InfoExtractor):
                     # the secret extracted from ya function in http://player.canalplus.fr/common/js/canalPlayer.js
                     'url': format_url + '?secret=pqzerjlsmdkjfoiuerhsdlfknaes',
                     'format_id': format_id,
-                    'preference': preference(format_id),
+                    'quality': preference(format_id),
                 })
         self._sort_formats(formats)