Misc. ui_next output work issue

[jakemcdermott]

• Decide if we're doing the multi-step output loading (ala Travis, GH Actions). This means we load high-level "header" * events on the first pass and load the line-by-line output for those events asynchronously on click. From a UI perspective, this approach is scalable for arbitrarily large jobs and will probably have a much simpler implementation and a better ux overall. I am very much for it. We should do this. This is a good idea. Do it.

* Header event = job event types that don't vary in quantity as a function of inventory size for a given playbook, e.g "TASK" and "Play" lines.

other tasks:

• hooks
• folding
• search

Putting a "blocked" label on this for now but not really blocked, just not ready for devel yet - We're still gathering facts and some of this warrants some discussion from various interested parties.