Improve archive information UI on project overview

Problem to solve

If a project is archived (read-only repository and database, not showing up in searches and dashboards), the project overview page shows a simple warning information. Right now, this info is shown on the Overview page only.

Let's make this UI more delightful.

Further details

• Example project on GitLab.com: https://gitlab.com/akaemmerle/example-project-archived01
• Current copy: Archived project! Repository and other project resources are read-only
• Out of scope: Further improve UX of read-only projects

Proposal

• Add an illustration with an​ additional title and description on the Project overview?
• System message?

What does success look like, and how can we measure that?

(If no way to measure success, link to an issue that will implement a way to measure this)