Adding a "reduce" option to the Smooth node

[cymplecy]

@Colin

I am having difficulty thinking of an application where this feature would be useful. Can you suggest an example?

I currently use node-red-contrib-aggregator to achieve same effect in my pool temp monitor.

The pool sends readings every sec and I average the readings over 60 secs and then pass that on to rest of flow

I wouldn't want to just send a single value to represent the 60 readings as it may be an outlier - I use the average (actually the median value) instead