Variable HEMISPHERE_UNIFORM_MEMBERS_WGSL`Const`

HEMISPHERE_UNIFORM_MEMBERS_WGSL: " hemisphereSky : vec4<f32>,\n hemisphereGround : vec4<f32>,\n hemisphereUp : vec4<f32>," = ...

The three hemisphere members, at HEMISPHERE_SKY_OFFSET. Shared with wgpu-shadow.ts so the shadowed and unshadowed structs cannot disagree about where sky, ground, and up live.