Saving x and y data when generating a plot

[joey-kilgore]

Is your feature request related to a problem? Please describe.
When using FigLogger.createPlot() it will save the plot object itself, but not the x and y data itself.

Describe the solution you'd like
Add an additional save that calls SimLogger.saveObj() for the x, y, (and z) data.

Describe alternatives you've considered
A user could save it on their own, but if the graph is being saved, the data for the graph should also be saved by default.