Fix a bunch of small issues with our GitHub comments viewer

[Urgau]

Just a bunch of small issues I saw and wanted to fix:

• Keep the badges round no matter the outer constraint
  • Before:
  • After:
• Wrap the issue/PR title if too long
  • Before:
  • After:
• Only make the cursor a pointer for review thread headers
• Add highlighting around the targeted (by url) comment or review-thread
  • 
• Add self-link to the author-ship time of each comment/review comment
• Add missing background color in suggested code
  • Before:
  • After:
• Make the reaction buttons so the emoji and number act as one entity

Testing links:

• http://localhost:8000/gh-comments/rust-lang/rust-forge/pull/1040#issuecomment-4267465591
• https://triage.rust-lang.org/gh-comments/rust-lang/rust-forge/pull/1040#discussion_r3100388285
• http://localhost:8000/gh-comments/rust-lang/rust/pull/155433

[Kobzol]

GitHub should really hire you at this point 😆 Great improvements, thanks!

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