Refine job explanation logic on output details panel

[mabashian]

Currently, the UI will only show the job explanation within the output portion of the details panel. I think the assumption here was that there would never be any lines of output so we could reuse this space. There are scenarios where there actually is output though:

We should re-think where we show the job explanation as a result. Here's an updated proposal where we use a banner just above the output:

Taking this approach should allow us to show the explanation in addition to the output when needed.

[mabashian]

@shanemcd dunno if you have a simple playbook that would reproduce this scenario but that may help the devs!

[keithjgrant]

we might want to do an "info" message rather than "error" since the job_explanation can be all sorts of things, not all of them an error, I think?