Frontend: Add an illustration in the Catalog index page

Overview

The current empty state page was minimally designed for the MVC. We could enhance it by providing additional actions and details to facilitate easier onboarding.

Proposal

Current	Proposal

• Add an illustration with 16px above from the text: https://gitlab.com/gitlab-org/gitlab-svgs/blob/main/illustrations/empty-state/empty-catalog-md.svg
• Figma link