Regression test for video writing

[jwnimmer-tri]

The ball_bin example video writing does not have any regression testing in our CI.

I assumed that since the --still mode worked, everything else would too, since VideoWriter is tested in Drake.

The problem is that import cv2 in Drake CI comes from Ubuntu, which has more codecs than the pip version of cv2, so in fact we were failing.

We should have a regression test to catch this in the future.

We will probably need RobotLocomotion/drake#19447 to land before the regression test would pass.