Probe nodes

Sometimes the spreadsheet is not ideal and requires some clicks, to choose the context, the domain. Things could be easier in some case with a probe node or mini viewer. A node that display the value of what is connected to it. Either the last value, the average or at index

I don't have much time so here is a quick mockup. but I could be one node

like the timings of nodes, it could be only computed when animation is not playing.