add a few potential tests for the pwdSimulator

Second verse, same at the first:

Sorta WIP. (In other words: the simulator is still marinating in my brain, and I may think of more and/or reconsider these tests.)

First two tests I added might be more for points of discussion, but I believe the third (re: settings change during a run of scheduled basals), which currently fails, poses more of a problem.

Whenever you're ready to discuss @cheddar @kentquirk
I think my opinion is that this is undesirable behavior. I can imagine a device that, for example, adjusts all of its own scheduled and temp basal events to include the proper (i.e., actual) duration before emitting/recording the data, so the simulator would be sorta unnecessary for those devices (unless they don't properly integrate suspend events or something), but we want to still be able to pass that data through the simulator and not have it erase those durations. Does that make sense?