[utils] Handle user:pass in URLs

[hhirtz]

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What is the purpose of your pull request?

• Bug fix
• Improvement
• New extractor
• New feature

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Description of your pull request and other information

Fixes "nonnumeric port" errors when youtube-dl is given URLs with
usernames and passwords such as:

http://username:password@example.com/myvideo.mp4

Refs:

• https://en.wikipedia.org/wiki/Basic_access_authentication
• https://tools.ietf.org/html/rfc1738#section-3.1
• https://docs.python.org/3.8/library/urllib.parse.html#urllib.parse.urlsplit

Fixes #18276 (point 4)
Fixes #20258
Fixes #26211 (see comment)

[jeanthom]

LGTM

[hhirtz]

Simplified the code and ticked the "improvement" box instead of the "bug fix" one

[hhirtz]

rebased the branch

[jeanthom]

still LGTM

[jeanthom]

Dear maintainers, please take some time to consider this issue, it finally adds a very important functionality to youtube-dl!

[dirkf]

Let's finally add this, but with a structure matching yt-dlp.

[dirkf]

Align with yt-dlp:

Suggested change

	return compat_urllib_request.Request(sanitize_url(url), *args, **kwargs)
	url = sanitize_url(url)
	url, username, password = extract_user_pass(url)
	if username is not None:
	# password is not None
	auth_payload = username + ':' + password
	auth_payload = base64.b64encode(auth_payload.encode('utf-8')).decode('utf-8')
	auth_header = 'Basic ' + auth_payload
	headers = args[1] if len(args) >= 2 else kwargs.setdefault('headers', {})
	headers['Authorization'] = auth_header
	url, auth_header = extract_basic_auth(escape_url(sanitize_url(url)))
	if auth_header is not None:
	headers = args[1] if len(args) > 1 else kwargs.get'headers')
	headers = headers or {}
	headers['Authorization'] = auth_header
	if len(args) <= 1 and kwargs.get('headers') is None:
	kwargs['headers'] = headers
	kwargs = compat_kwargs(kwargs)

[dirkf]

Align with yt-dlp:

Suggested change

extract_user_pass,