Empty state for Starred Projects

What does this MR do?

This MR improves the empty state of starred projects.

before	after

What are the relevant issue numbers?

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/34555

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the style guides

Still todo

• Update the illustration from gitlab-svgs!193 (merged)