Store joint video

@ckv0173 pointed out here:

One important feature is still missing: normally, during development, you would want to see both the rendering and the metrics at the same time. However, sometimes, viewing only one of the two is sufficient. My suggestion is to extend the close_video_recorder function, such that when storing the videos it generates an additional(!) joint video one where the metrics is right of the 3D rendering. This should be doable as shown here: https://karobben.github.io/2021/04/10/Python/opencv-v-paste/