Allow !PU(funnel) to accept linked values in addition to transforming a USQL funnel

[TechShady]

We now have custom session metrics. You can create a metric for each step, place them on a dashboard and then identify each step (tile) with a link. Having the steps in a funnel would be the best way to visualize the data and would eliminate extrapolation that hampers USQL with large data volumes. So something like !PU(funnel):links=step1,step2,step3,step4,step5.