Visualizations: add data for upset plot of missingness to all existing visualization endpoints

[d-callan]

this is still being discussed. but its possible well need, in addition to the completeCasesTable a table of intersections of completeness across the vars plotted. it might be returned separately (beside the completeCasesTable) or as part of a larger upsetPlot object..

[d-callan]

starting to look like well need a table of intersections instead of the completeCasesTable

[d-callan]

think this is moved to the missingness app for phase 2

[d-callan]

need more information here before costing as well. is this a thing we want for each viz in the pass app, or solely in the missingness app? and which of those are priority?