Support sampling and throttling

[vjsamuel]

It maybe a good idea to implement mechanisms through which we can dynamically start sampling the data from a source and also completely throttle events. This gives us the flexibility to dynamically change configs of a prospector to start sampling/throttling data from a give source if downstream starts to complain of over whelming data rates.

[monicasarbu]

Related to: #1721 for Packetbeat.

[lcaballero]

@vjsamuel I was thinking along the same lines. I started a suggestion for the idea: Rate limit published event. Perhaps you can add a comment and provide some ideas about what the end implementation might look like.

[wu0407]

need this function

[mostlyjason]

I created a new meta-issue to track this request. Closing this one for now.

[amomchilov]

@mostlyjason Could you link it with this one, please?

[mostlyjason]

@amomchilov posted here #17775