31689 Add default margin-top to user request table on project members page

What does this MR do?

Adds default margin-top to table for user requesting membership to projects

Screenshots (if relevant)

Before:

After:

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #31689 (closed)