[Pornbox] New extractor

[niemands]

IMPORTANT: PRs without the template will be CLOSED

Description of your pull request and other information

This extractor adds support for videos on pornbox.com. Most of the videos on the site must be purchased individually or are accessible via channel membership options. The test case is for one of the few free promotional videos. However, it still requires an account.
This extractor can return metadata with --dump-json and --ignore-no-formats, but otherwise requires cookie authentication.

Template

Before submitting a pull request make sure you have:

• At least skimmed through contributing guidelines including yt-dlp coding conventions
• Searched the bugtracker for similar pull requests
• Checked the code with flake8 and ran relevant tests

In order to be accepted and merged into yt-dlp each piece of code must be in public domain or released under Unlicense. Check all of the following options that apply:

• I am the original author of this code and I am willing to release it under Unlicense
• I am not the original author of this code but it is in public domain or released under Unlicense (provide reliable evidence)

What is the purpose of your pull request?

• Fix or improvement to an extractor (Make sure to add/update tests)
• New extractor (Piracy websites will not be accepted)
• Core bug fix/improvement
• New feature (It is strongly recommended to open an issue first)

Copilot Summary

🤖 Generated by Copilot at 6ff3131

Summary

🚀🗣️🛠️

Add support for --write-link and --write-url options to write video or playlist URLs to a file. Refactor the code for writing metadata files to avoid duplication and improve readability.

get and set methods
refactored for readability
autumn leaves falling

Walkthrough

• Add new extractors for various video platforms (F0L

[pukkandan]

nitpicks

[niemands]

Thank you for re-visiting my PR. I had to replace the first test case with a new video because the old one was no longer available, and as far as I can see this is one of the four remaining free videos, so I'm not sure if this test case will work for long. However, it passes the test.