This builds on API changes in #6017 and #6021 to conditionally turn off the
“Run Job” button based on the current token’s capabilities, or the capabilities
of the anonymous policy if no token is present.
If you try to visit the job-run route directly, it redirects to the job list.
This uses ember-page-title to add dynamic page titles throughout the
route hierarchy. When there’s more than one region, the current
current region is added before the final entry of “- Nomad”.