get points from ScatterPlotListDraggable

**System Details**
**ScottPlot Version:** 4.1.64
**Operating System:** Windows 11
**Application Type:** WinForms

**Question:** 

If I have a:

```cs
var scatter = new ScottPlot.Plottable.ScatterPlotListDraggable();
scatter.AddRange(xs, ys);
```
How do I get the positions of the points after they have been dragged?
