Root CMS custom status badges

[stevenle]

Description

For sites that integrate with CI, it would be cool to have status badges be displayed in the UI (possibly on the top left). Example use case would be to display the current build status (e.g. red for broken builds, yellow for pending/ongoing builds, green for success) or last deployed timestamp.

[stevenle]

To help build tools with this request, we should also have a root-cms cli command that helps set this metadata, something like:

root-cms metadata.set badges.build_status {"color": "green", "message": "...", "href": "https://example.com/buildtool/"}