Experiments: Show status of CI workflows

[daavoo]

Given that:

DVC Studio uses your regular CI/CD setup (e.g. GitHub Actions) to run the experiments.

I think it would be nice to display the status of the CI/CD workflows in order to be able to better monitor the experiments directly from Studio.

[dberenbaum]

Maybe related to #59? Being able to see the stage of the pipeline that's currently active, the results of each completed stage, and the time spent in each is something I would use for a long-running job.

[dberenbaum]

Not sure if this should be a separate request, but similar functionality would be useful to check if commits are up to date: show that all stages have a clean status and everything from them has been pushed. Related to #81 (comment).