Buttons disappear on merge request page in some case

What does this MR do?

Makes buttons always shown on title on Issue/Merge Request detail page.

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

CSS.

Why was this MR needed?

Buttons are (partially or fully) hidden when user's name is longer (about more than 70 characters).

Screenshots (if relevant)

Issue

before	after

Merge Request

before	after

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
• Conform by the code review guidelines
  • Has been reviewed by a UX Designer
  • Has been reviewed by a Frontend maintainer
  • [n/a] Has been reviewed by a Backend maintainer
  • [n/a] Has been reviewed by a Database specialist
• Conform by the merge request performance guides
• Conform by the style guides
• [n/a] If you have multiple commits, please combine them into a few logically organized commits by squashing them
• [n/a] Internationalization required/considered
• [n/a] End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

Closes #46861 (closed) and #14348 (closed)