[frontend] add lunchpail benchmark feature to show metrics

[aavarghese]

A dashboard to view lunchpail metrics for a lunchpail with/without specific appplication...

completion rate
est. time of completion...per worker, per pool etc
est. time of enqueue

VPC resources cost

[starpit]

nice! the term benchmark implies that there is an aspect of simulation. whereas i think what is meant here is to have a dashboard to run along with or instead of pkg/observe/status. whereas the status dashboard highlights task flow and logs, this proposed dashboard would focus on metrics.