[UI] Update warning label with latest commit

[adong]

What happened: When people start an old commit, we show a warning, see the screenshot below:

What you expected to happen: Instead of showing just a warning, we can add the actually latest commit sha for people to compare:

Maybe we can even add the latest event url there, so devs can click and redirect to the latest commit sha's event.

How to reproduce it: Restart from an old build

[jithine]

I don't think just showing the commit sha for latest is useful here or actionable. Intention should be to enable users to run to job with latest sha, something which jobs view can do.