Improve mobile UI on User Profile page

What does this MR do?

Pulls Edit/RSS buttons on top to right on a User Profile page on mobile to gain 54px height (which is > 10% of 460 px on iPhone 5S, or 6.6% of 812px even on iPhone XS).

cases	img
before
after

This affects https://gitlab.com/help/ui (only on mobile) as well, but it works as well.

What are the relevant issue numbers?

Closes #59057 (closed)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• [n/a] Documentation created/updated via this MR
• [n/a] Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• [n/a] Conforms to the database guides
• [n/a] Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• [n/a] Security reports checked/validated by reviewer