Update wiki sitemap

What does this MR do and why?

• Adds New page button to wiki sitemap
• Fix alignment of nested items
• Reorders buttons (at some point the sort button could probably be moved to its own line 🤔)

Screenshots or screen recordings

Before	After

How to set up and validate locally

Go to All pages/wiki sitemap (eg http://127.0.0.1:3000/flightjs/Flight/-/wikis/pages)

Links

• ✂️ UX Paper Cuts 17.1 → Improve Wiki Experience (#452225 - closed)