Resolve "Improve Auto DevOps settings flow for admin and project"

What does this MR do?

• Changes the styling and copy of the instance-wide Auto DevOps setting.
• Changes the copy of the per-project Auto DevOps setting
• Simplifies the per-project Auto DevOps setting from three radio boxes into a single checkbox, abstracting away the "instance default" inferred setting.

Screenshots (if relevant)

Instance (Admin) Settings

before	after

Project Settings

before	after

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
  • Has been reviewed by a UX Designer
  • Has been reviewed by a Frontend maintainer
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• If you have multiple commits, please combine them into a few logically organized commits by squashing them
• Internationalization required/considered
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

Closes #47156 (closed)