Improve "Wait time to pick a job" graph in Runner Fleet dashboard
I feel we could add more context to the graph to help the user make sense of the outliers. A low-hanging fruit would be to draw the 99 and 50 percentiles either as areas or lines in the graph, e.g. (sorry for lame image editing work):
![image](data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==)