[vlive] add support for new url format

[kyuyeunk]

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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

This pull request solves the issue #27122.

The code determines if a url is old type or new type. And for fetching data, it uses post/v1.0/officialVideoPost-<videoId> for old type and post/v1.0/post-<postId> for new type.

Example of a new url is added in _TESTS.