MeshBasicNodeMaterial: Add envMap support.

[Mugen87]

Related issue: #28785

Description

I thought I give it a go and add envMap support to MeshBasicNodeMaterial.

It seems a similar change must be implemented for MeshLambertNodeMaterial and MeshPhongNodeMaterial since both materials types should sample environment maps in the same fashion.

BTW: NodeMaterial must distinct somehow which materials should use EnvironmentNode and which should use the code from this PR. Only PBR materials support Scene.environment and PMREM and that is what EnvironmentNode is about.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

Filesize dev	Filesize PR	Diff
682.2 kB (169 kB)	682.2 kB (169 kB)	+0 B

🌳 Bundle size after tree-shaking

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

Filesize dev	Filesize PR	Diff
459.4 kB (110.9 kB)	459.4 kB (110.9 kB)	+0 B

[sunag]

It seems a similar change must be implemented for MeshLambertNodeMaterial and MeshPhongNodeMaterial since both materials types should sample environment maps in the same fashion.

In this case, it would be interesting to have an intermediate Node with this code.