Plot resizing on trace toggle

[mdtusz]

@alexcjohnson @etpinard

When plotting certain plots (not sure what the required condition is), the plot width will change when a trace is toggled.
For example, use the mock pseudo_html.json.

Immediately after plotting:

(the cut off section isn't due to the screenshot)

After toggling a trace:

This seems to be happening after a second redraw - the mock in question passes the image tests because the method for rendering images redraws and calculates the changed width.

[mdtusz]

Fixed in PR #243