Selection box ghost after reset on 2d density map

[Birm]

The selection box for 2d density was fixed in #105 , but now there's an edge case where resetting the filters does indeed reset the plot, but not the outline of the previous selection box (until another one is selected).

[Mohamed Nasser]

I can fix it by removing the selected area after the end of the drag as it is in the scatter plot.
Or you want it in another way?