Show statistics on selection during infusion at high flow

If we accept the premise that optimisation is best when variation in signal is minimum then having tools to evaluate your variation in signal during split-flow infusion could be useful for generating better conditions.

Idea: 

- allow a selection to follow the current acquisition and report CV of values as the infusion continues.

UUID for my reference:

6d2a36c5-ad4b-4281-4511-2e51f72f83e0