Visualizer should show animation when stepping through frames

[erdman]

trafficstars

When visualizing a match, there are animations that clearly show which piece is moving where. When the visualization is paused with space bar to allow frame-by-frame stepping, the animations no longer show, making it VERY difficult to see precisely what is happening in each frame. Please show the animations when single-frame stepping in the visualizer.

[truell20]

Totally agree. Thanks for the feature request!