[BiliBili] - Few adjustments to the BiliIntlIE class

[SirElderling]

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Description of your pull request and other information

This pull request contains a few adjustments to the BiliIntlIE class

• Add the 'Referer: https://www.bilibili.tv/' header to the download procedure
  Should permanently fix issues such as:
  bilibilitv: download breaks after 8388608 #8773
  BiliBili.tv downloads causing different error messages #6640

• Fix warnings for failed extractions:

WARNING: [BiliIntl] unable to extract JSON-LD ; please report this issue on  https://github.com/yt-dlp/yt-dlp/issues?q= , filling out the appropriate issue template. Confirm you are on the latest version using  yt-dlp -U
WARNING: [BiliIntl] unable to extract og:title; please report this issue on  https://github.com/yt-dlp/yt-dlp/issues?q= , filling out the appropriate issue template. Confirm you are on the latest version using  yt-dlp -U
WARNING: [BiliIntl] unable to extract og:description; please report this issue on  https://github.com/yt-dlp/yt-dlp/issues?q= , filling out the appropriate issue template. Confirm you are on the latest version using  yt-dlp -U

• Removed a 404 test

• Added timestamp and description extraction to the _parse_video_metadata function.

Note: I was unable to run many of the tests for the BiliIntlIE class due to geo block.

Template

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• Checked the code with flake8 and ran relevant tests

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[seproDev]

The header changes are also part of #7077

[SirElderling]

The header changes are also part of #7077

With the assumption that #7077 will be merged, should I remove the headers part from my PR?

[seproDev]

No need. I removed the header changes from #7077, so they are now only here.

[SirElderling]

The thumbnail property for the test'url': 'https://www.bilibili.tv/en/video/2045730385' sometimes returns akamaized.net instead of akamaized.com. I adjusted the test to reflect that.