Add tooltips for decomposition tree

Please add tooltips to the fabulous decomp tree visual.

For example, I have a chart that shows a measure of cycle time. THe decomp visual does a great job at allowing the users to drill into what's driving that number, but often times there maybe a very low volume item that is significantly driving the measure. I don't care if a product has a really long cycle time if it's not material in the overall calculation.

Specifically, looking at median measures. I need to understand the volume of each item. An easy way to do this is via a tooltip.