Donut graph is misleading...percentages don't show properly

[pbr6cornell]

i was examining one of the donut graphs for observation period and i realized that the portion showed in the slice didn't match up with the proportion.

the reason, best i can tell, is that 1) there's whitespace between slices, and 2) there's a minimum slice width required. when you combine those two 'features', we had a donut where a 90% category only took up 75% of the graph!

we likely need to figure out a different visualization to include in the OHDSI visualizsatoin library for representing categorical variables, one which doesn't distort the data in this way. posting this issue on ACHILLES since that's where i found the issue, but really this will need to be an issue addressed as the vizualization library is built out as part of the shared component library in ATLAS.