Using https://github.com/asottile/pyupgrade
1. `__future__` imports and `coding: utf-8` were removed
2. Files were rewritten with `pyupgrade --py36-plus --keep-percent-format`
3. f-strings were cherry-picked from `pyupgrade --py36-plus`
Extractors are left untouched (except removing header) to avoid unnecessary merge conflicts
* Prefer use of manifest based on `releasePid` since the one based on `videoPid` may have Fairplay
* Additional thumbnail images were added
* Don't add `season_number` and `series` to `title`
* `series` is now set to `None` rather than "_" when empty
* fix bug with age limit
Authored by: 2ShedsJackson
* All modules and binary names are changed
* All documentation references changed
* yt-dlp no longer loads youtube-dlc config files
* All URLs changed to point to organization account
Co-authored-by: Pccode66
Co-authored-by: pukkandan
