Show visual indicator that cluster agent is available for project [RUN ALL RSPEC] [RUN AS-IF-FOSS]

What does this MR do?

Show visual indicator that cluster agent is available for project

Screenshots (strongly suggested)

On GitLab.com only, if project is enabled for KAS:

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • [-] I have not included a changelog entry because _____.
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers