Resolve "Gitlab administrator cannot create projects in every group"

What does this MR do?

Allows administrators to create projects in private groups without being members.

Why was this MR needed?

To avoid having to add admin as a member of a private group before creating a new project.

Does this MR meet the acceptance criteria?

• Changelog entry added
• 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 #27910 (closed)