Improve failures user experience

[dcramer]

Right now when there's a selenium failure, we sometimes get a failing unit test, but we always get a resulting artifact.

It would be useful, at the very least, to show artifacts bundled as part of each job (maybe click to expand) on the overview. We could replace the artifact list with this (not on the dedicated tab).

On the dedicated tab we should annotate with which job its from.

Additionally, it probably makes sense at this stage to pull out a dedicated test details page, both per build and per project.

• Per project should include test history (e.g. flakiness)
• Per build should additionally include relevant artifacts to that job, since they could be related to the failure