BatchedMesh, InstancedMesh: add support for negative scaled, back side rendering

[gkjohnson]

Related issue: #30327

Description

Multiplies the normal by the sign of the determinant of the instance / batch matrix so the normal is facing the right direction in cases where the matrix has a negative scale.

Unfortunately I don't think there's a lot that can be done in terms of automatically fixing the triangle winding order when using a negatively-scaled matrix but this lets the user use double sided rendering if desired.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	339.53 79.09	339.58 79.11	+56 B +20 B
WebGPU	493.59 137.22	493.59 137.22	+0 B +0 B
WebGPU Nodes	493.05 137.12	493.05 137.12	+0 B +0 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	465.41 112.16	465.46 112.17	+56 B +14 B
WebGPU	564.12 152.88	564.12 152.88	+0 B +0 B
WebGPU Nodes	519.5 142.46	519.5 142.46	+0 B +0 B

[WestLangley]

I am inclined to think that we should not attempt to support mixing positive and negatively-scaled instance/batch matrices in the same draw call -- unless the implementation works in every use case.

Instead, just say negative scales in the instance/batch matrix are not supported.