msWaitingForMongot is updated in getNext(), but that means that it may be a bit "behind" the reality. For example, in HELP-79325 there was confusion because we will always report msWaitingForMongot=0 if {batchSize: 0} since we will never call getNext() even though we do dispatch a mongot request (and possibly wait for the response? unclear).

My proposal is to attempt to update msWaitingForMongot when we receive a response from mongot, instead of waiting for the getNext(), if possible.

Maybe we should also add a flag to indicate if we have an in-flight mongot request? That might help clarify the reality of what msWaitingForMongot represents

We should also add better inline comment and maybe loglines so that we overall have a better sense of these stats and what they represent.