Show `failure_reason` and improve failed jobs tab in pipeline detail view

This issue is part of https://gitlab.com/gitlab-org/gitlab-ce/issues/41111

Design

• If error categorisation has a job log, have inspect button and part of job log
• If error categorisation hs no job log, have retry button and empty state job log

• If retry button is clicked => same functionality as the jobs tab, which just refreshed the whole page. (vue refactor is out of scope)

• When a job is retried, it vanishes from the failed pipelines tab (still discoverable in the jobs list)

Note: Inspect button is not to be implemented! Job title will link to job detail page already