Rework the build view UI

[flynnduism]

Following on from #258. The UI for the build + job info could better balance metadata and logs for the different elements.

The worker logs (black textarea at the bottom) are a bit buried, shown after the build is finished, though this is running in parallel to the jobs. I think a tabbed approach could be useful to balance keeping the top level info and the logs in view at the same time.

[radu-matei]

This would be amazing!

[radu-matei]

ref #33 #14 #213

[carolynvs]

This would be really helpful. For builds with lots of steps, it can be a very long scroll to find the part that failed and find the relevant logs.

[krancour]

Highly in favor of this.

cc @danieldelao

[krancour]

Closing due to staleness, but please do reopen if necessary.