* [utils] Create `RetryManager`
* Migrate all retries to use the manager
* [extractor] Add wrapper methods for convenience
* Standardize console messages for retries
* Add `--retry-sleep` for extractors
* [youtube] Fix `--youtube-skip-dash-manifest`
* [build] Use `$()` in `Makefile`. Closes#3684
* Fix bug in 385ffb467b
* Fix bug in 43d7f5a5d0
* [cleanup] Remove unnecessary `utf-8` from `str.encode`/`bytes.decode`
* [utils] LazyList: Expose unnecessarily "protected" attributes
and other minor cleanup
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
* `player_client` accepts multiple clients
* default `player_client` = `android,web`
* music clients can be specifically requested
* Add IOS `player_client`
* Hide live dash since they can't be downloaded
Closes#501
Authored-by: pukkandan, colethedj
* 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
sepro