Add ability to configure events, duration during a run

[ZLLentz]

Expected Behavior

Daq.configure needs to be callable in the middle of a bluesky plan if we want to change the length of a trigger_and_read call, e.g. run for x events and then change something and run for y events.

Current Behavior

Cannot call configure at all if a run is open.

Possible Solution

Only the first configure and changes to record state should actually trigger a pydaq.Control.configure call. Every other configurable should be saved and passed through to pydaq.Control.begin.

Context

There are use cases for taking n dark shots and m light shots, where n!=m, and this pattern looks something like:

yield from configure(daq, record=True)
yield from open_run()
yield from configure(daq, events=n)
yield from trigger_and_read(daq)
yield from configure(daq, events=m)
yield from trigger_and_read(daq)
yield from close_run()

[slactjohnson]

@ZLLentz I would like to take a swing at this (MEC needs this functionality), but I think I need to discuss with you first. Do you have some time to talk about this in the next week or so?

[ZLLentz]

Hey @slactjohnson, happy to talk about this any time. We could review the code together, I don't quite remember what it looks like.

[slactjohnson]

@ZLLentz Sounds good. Let's plan on next week.