Add Accordion for Experimental Settings (New Project)

What does this MR do and why?

Adds an Accordion component and uses it on the New Project page to wrap experimental settings.

Contributes to #433130 (closed)

Screenshots or screen recordings

How to set up and validate locally

1. Enable the support_sha256_repositories feature flag.
2. Visit create new project page (http://gdk.test:3000/projects/new#blank_project)

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.