Drop Subtitle parsing

[suorcd]

Sounds like the Apple podcast index does not parse this information.
Reducing what is parsed would help with our load.

Once the field is not parsed we could drop the column in the episodes table.

[mitchdowney]

Ok...a couple years ago someone actually requested we put subtitle support in. If a subtitle is not available, our apps fallback to use description. Even though Apple and PI have deprecated it, I'm not entirely sure I want to drop it as long as some podcasts are using it. The idea is a subtitle is a shorter "description" which gets used in list views. I queried our database and there are ~37 million episodes with a value in the subtitle column.