Add support for selecting highest quality audio track for each language when "best" is specified

[Sp5rky]

• The modified code checks if "all" is present in the lang list.
• If "all" is found, it retrieves a set of unique languages from the available audio tracks.
• For each unique language, it iterates through the audio tracks and finds the track with the highest bitrate.
• It then adds the highest quality track for each language to the selected_audio list.
• Finally, it sets the title.tracks.audio to the selected_audio list, containing the highest quality track for each language.
• If "all" is not found in the lang list, the existing behavior for specific language selection is maintained.

Fixes https://github.com/devine-dl/devine/issues/93

[Sp5rky]

Changed naming of -l all to -l best as I feel its easier to understand