This closes#7454. It makes use of the existing watchable tools to
allow the exec popup sidebar to be live-updating. It also adds
alphabetic sorting of task groups and tasks.
This closes#7476. The decomposition of computed properties
is necessary to avoid nested aggregate dependent keys; the
previous dependent key of `taskGroup` will be inadequate
when the sidebar becomes live-updating.
This connects Xterm.js to a Nomad exec websocket so people
can interact on clients via live sessions. There are buttons on
job, allocation, task group, and task detail pages that open a
popup that lets them edit their shell command and start a
session.
More is to come, as recorded in issues.
