make possible to disable throttling mode for some triggers

[vraskoshnyy]

need a function to disable throttling mode for some triggers

Summary

often need to work with triggers like this groupByNode(dc.host.app.requests.incoming...process_time.failed.count, 6, 'sum'),
in time of major app failure, a large number of notifications are generated simultaneously and throttling mode blocks sending of notification. As a result, Moira sends the first notification to telegram only after 30 minutes, and Moira will send the next notification 1 hour after the event occurs.
In total, we receive the first notification not in time of the event, but with a delay of 30 minutes.
However, in other cases, throttling mode is needed and works as expected.

Unfortunately, I can't use the recommendations for disabling throttling from documentation section https://moira.readthedocs.io/en/latest/user_guide/throttling.html#disabling-throttling