Add "Rendering" Overlay #65
Description
For long runs that result is large result sets, it can take several seconds to render all the graphs. During the run itself we get a counter of the time elapsed and the time estimates graph now animates to show that work is happening, but between the finish of the run and the final displays everything just stops. It would be helpful to have an overlay that makes it clear what's happening.
Add an overlay that greys out the page, and reads "Completing Final Processing" that appears when the simulation run ends. The overlay should disappear when all processing of numbers are complete and graphs are ready to render.