Godot version

Godot 4 dev, 55dae30

System information

Fedora Linux, Intel A750

Issue description

possibly related to #14403, but since it is a more specific issue with clearcoat, I'll add it here:

Please consider the attached screenshot to illustrate the issue. Right now, when enabling Clearcoat in StandardMaterial3D, all Normal Map detail gets basically lost und covered under an even layer of gloss. Unless I misinterpret the use case of Clearcoat, I don't think this is mostly desirable.

If you want to use Clearcoat e.g. to add wet areas to a surface material, it will look absolutely horrible. I would expect Clearcoat to have basically the same effect as reducing the roughness of a material (i.e. taking the normal map into account). Right now this doesn't seem to be the case as shown in the screenshot below. In both cases the same normal map is used.

Steps to reproduce

1. Create/import a model and add a StandardMaterial3D
2. Add a normal map to it (e.g. Noise Texture)
3. Enable Clearcoat and see the normal map detail disappear

Minimal reproduction project

Clearcoat_Test.zip