Add sub-nav for Project Integration Services edit page

What does this MR do?

Services' edit page under Project -> Settings -> Integration doesn't show sub-nav, this MR adds missing sub-nav.

Why was this MR needed?

Since we moved project settings from dropdown menu to nav tab, sub-nav is not shown in services' edit page, this MR fixes the same.

Screenshots

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 #31174 (closed)