MIKKTSpace normal mapping

New tangent_space_type option for normal_map: A new tangent_space_type parameter adds support for MIKKTSpace normal mapping. The standard mode preserves the previous behavior, while the mikk mode imports normal, tangent, and bitangent generated with MIKKTSpace in DCC tools such as 3ds Max and evaluates the normal map using MIKKTSpace for consistent shading across applications. (ARNOLD-8377)