Add cancellation reason to `hq job cancel`

[Kobzol]

Is it currently possible to add a reason when cancelling a job? Something like hq job cancel 42 --reason="Accidentally used wrong binary" or hq job cancel 43 --reason="submitted to wrong alloc"?
If not, I think it would be a great addition, as it would allow one to retrospectively do hq job list --all and be reminded of why one cancelled these jobs and resubmitted them.

Asked on Zulip by @StHagel.

It think it would be a nice addition, WDYT @spirali?

[spirali]

I agree. We already have a state with an attached message (error state) so it is not a difficult to extend this.