Poor UX with branch whose name is very long on Branches

What does this MR do?

Re-designs UX of branches by modifying HTML structures and CSS.

Are there points in the code the reviewer needs to double check?

No. Note that a longer commit message line was not fully optimized, which is out of scope of this MR, as some fix affects other pages.

Why was this MR needed?

Because UI with a branch whose name is very long and/or whose last commit has a long commit message is broken on Branches. And to simplify HTML structure around it.

Screenshots (Version 2)

Cases	Images
PC
PC (narrower)
mobile
mobile (narrower)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• [n/a] Documentation created/updated
• [n/a] API support added
• [n/a] Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • [n/a] Has been reviewed by Backend
  • [n/a] Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• [n/a] Internationalization required/considered
• [n/a] End-to-end tests pass (package-qa manual pipeline job)

What are the relevant issue numbers?

Closes #44386 (closed)