Draft: Add sticky table of contents to project CI/CD settings

🐙 Note: This is a proof of concept and is not likely to be merged

• If we want to move forward with something like this, I suspect we'd need a lot more help from engineering to build it out in a scalable way
• Please continue to post any ideas!
• Feel free to commit directly to this branch (but please don't squash any commits)

What does this MR do and why?

• Expands all settings sections in the project CI/CD settings
• Removes the expand/collapse buttons
• Adds a sticky table of contents

Future enhancements

• UI styles could be updated
• Add active state that updates on scroll
• Fix spacing
• Update runners two-column UI?
• Mobile version

Screenshots or screen recordings

Before	After

How to set up and validate locally

Go to Project > settings > CI/CD

UX Paper Cuts 16.2 → Settings UI (#398215 - closed)

UX Paper Cuts 16.3 → Settings UI, part 2 (#417912 - closed)