3D Volumetric Rendering from Point Cloud Data

## What problem does this solve or what need does it fill?
In the medical data domain, as well as a lot of other domains, data is represented as 2D or 3D dense textures/volumes which can be interpreted as point clouds.

Currently, Bevy has a lot of potential for creating advanced visualization and rendering of 3D objects, but it lacks in directly rendering a 3D volume.

## What solution would you like?

A way to directly render 3D data, or an interface for that, coupled with the necessary shader/rendering of the structures.

## What alternative(s) have you considered?

Other tools, but this leads away from Bevy. Examples from the medical domain:

3D Slicer: https://github.com/Slicer/Slicer
VTK: https://github.com/Kitware/VTK
NiiVue: https://github.com/niivue/niivue

## Additional context
None.