Port of subsurface scattering from the eevee-rewrite branch to EEVEE Next. https://projects.blender.org/fclem/blender/src/branch/eevee-rewrite Other changes: * Fix gbuffer normal and ior packing. * Write the material eClosureBits to the gbuffer stencil. Known Issues: * Transmittance profile pre-computation is wrong. Pull Request: https://projects.blender.org/blender/blender/pulls/107407