[extractor/cda] Fix age restriction

[Podiumnoche]

IMPORTANT: PRs without the template will be CLOSED

Description of your pull request and other information

Update to PR #6638

This pull request updates age confirmation to work with the new form. The code is as it was proposed by @emqi, the original poster of #5980.

Looks like https://github.com/Szpachlarz is not active, so I updated it according to #6638 (comment). I hope it's ready to merge, write me if anything more requires to be updated.

Fixes #5980

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:

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• Fix or improvement to an extractor (Make sure to add/update tests)
• New extractor (Piracy websites will not be accepted)
• Core bug fix/improvement
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[Podiumnoche]

@selfisekai could you take a look?

[selfisekai]

LGTM

[bashonly]

Note to self: when merging, remember to close original PR along with the issue, and credit the original PR author as well as the issue author