Caveat with value throttling: queue statistics show real update time, not poll time

There is a caveat with preprocessing of change throttling (update when changed / update when changed with heartbeat).

We've started using that for multiple items, with 'heartbeat' interval of hours up to entire day.

Queue display started showing all such items in above 10 minutes. While it's correct because item was not actually updated for long (no changes), it is totally misleading, because item was actually polled, and looks like there is some polling problem (indistinguishable from polling issues).

The solution to distinguish between throttling and polling issue on queue view can be recording actual poll time for the item instead of the update time, and using this poll time for queue view display.