Feature request: shaded wireframe display mode

I would like to see a new Debug Channel view mode, to see the wireframe. This would be very helpful to evaluate geometry compression methods.

It's not helpful to use a simple wireframe view, for example as used in the Three.js Editor, because it's difficult to visually assess the topology:

In DGG's current viewer (based on Babylon.js) we show black wireframe on white, which is occluded, and this is helpful:

However even better would be to have a gray model behind the occluded wireframe, to show both shading and wire at the same time, as is the case here in 3ds Max:

Hopefully this display mode would work with the glTF Compressor A/B slider, to compare before/after topologies.

Start at the Debug Channel view-mode entry point and inspect how the glTF Compressor A/B slider selects its before-and-after displays. Confirm how the current wireframe mode is rendered, then define done as a shaded model remaining visible behind the wireframe in both comparison states.

Written by the indexing model from the issue text.