Add the ability to manually run a check or notification rule for debugging

from a user: when creating a check or notificationRule, he would like the ability to run them adhoc to verify they are working instead of having to wait for the interval.

The issue does not name files, tests, or entry points. Start by locating the check and notification-rule scheduling paths and determine how an ad hoc run should be requested and reported. Done means a user can manually run either rule for debugging without waiting for its interval, with coverage for the resulting behavior.

Written by the indexing model from the issue text.