Any logged image should set the default for a set of 2D canvas settings. These settings are part of the SpaceView settings and will have top left and the size. They can be set manually there but would default to a simple heuristic: Exact size of the combination of all images. If no images, make geometry visible with some margin.

Note that today the viewport is set every frame to the accumulated bounding box which is a bit problematic for various scenarios.

Loosely related to #349