Implement extension for code coverage badges

[jonesbusy]

Can be a plugin if not integration to core plugin.

See https://community.jenkins.io/t/how-to-use-embeddable-build-status-plugin-to-display-code-coverage/11463/3

• Missing some test
• Perhaps other metrics can be added in the future
• Missing documentation

Testing done

Automated tests and interactive

Submitter checklist

Beta Give feedback

1. Make sure you are opening from a topic/feature/bugfix branch (right side) and not your main branch!
2. Ensure that the pull request title represents the desired changelog entry
3. Please describe what you did
4. Link to relevant issues in GitHub or Jira
5. Link to relevant pull requests, esp. upstream and downstream changes
6. Ensure you have provided tests - that demonstrates feature works or fixes the issue