* Move Brightcove embed extraction and tests into the IEs
* Split `BrightcoveNewBaseIE` from `BrightcoveNewIE`
* Fix bug in ade1fa70cb with the "wrong" spelling of `referrer` being smuggled
Closes#5539
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
* 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
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