Plan Area Update

We've overhauled the plan area at the bottom of each metric page!

Previously there were two "widgets": A listing of plans and a pie chart of how those plans made up each metric.

The pie chart wasn't terribly useful due to the fact that most people have far more plans than can reasonably fit in a pie chart, so we combined that % into the plan listing itself!

This also sets the stage for some near-future improvements to Segmentation!