ENH: add resume thresholds to suspender justification message

[tacaswell]

Description

Adds more context to the justification emitted by the suspenders.

Motivation and Context

Not including the resume condition lead beamline staff to become concerned we were doing "new math".

How Has This Been Tested?

Covered by existing test cases, however we do no check the contents of stdout, disabling capture and running the tests locally gives

.Suspending....To get prompt hit Ctrl-C twice to pause.
Suspension occurred at 2022-12-08 13:25:32.
Justification for this suspension:
Signal bool_sig = 0 fell below 0.5 and has not yet crossed above 0.5.
Suspender SuspendFloor(Signal(name='bool_sig', value=1, timestamp=1670523933.1577613), sleep=0.2, pre_plan=None, post_plan=None,tripped_message=) reports a return to nominal conditions. Will sleep for 0.2 seconds and then release suspension at 2022-12-08 13:25:33.
0.9057326316833496
.Suspending....To get prompt hit Ctrl-C twice to pause.
Suspension occurred at 2022-12-08 13:25:33.
Justification for this suspension:
Signal bool_sig = 1 went above 0.5 and has not yet crossed below 0.5.
Suspender SuspendCeil(Signal(name='bool_sig', value=0, timestamp=1670523934.2849662), sleep=0.2, pre_plan=None, post_plan=None,tripped_message=) reports a return to nominal conditions. Will sleep for 0.2 seconds and then release suspension at 2022-12-08 13:25:34.
0.9056258201599121

[ZLLentz]

This is a clear improvement

[mrakitin]

Indeed, that's very helpful, thanks @tacaswell!