[CSG]: Camera starts at hardcoded position

[Cloud7050]

CSG currently uses a hacky method of setting the initial camera position, adopted from the way JSCAD does it on their website. The camera starts at extremely far coordinates, then uses the "zoom to fit" feature (which is also run upon the initial render) to zoom to an extremely small scale.

https://github.com/Cloud7050/modules/blob/9624a2619e5055e6a33490204e319fbb0efd2f86/src/bundles/csg/stateful_renderer.ts#L38

In theory, if Operables are scaled to an extremely large size when rendered, the initial camera position can be inside a Shape and the camera direction calculations may bug out.

Ideally, a dynamic starting camera position will get calculated based on the actual bounds of everything being rendered.

See also Cloud7050#7