OCIO environment variable behavior follows 3ds Max color management settings

The color management setup in 3ds Max 2025 has explicit modes to use different OCIO configurations: a default mode, a custom mode, and a mode to follow the OCIO environment variable. MAXtoA passes this mode setting on to the Arnold renderer so that Arnold uses the OCIO environment variable override only when 3ds Max is explicitly set in the OCIO - Environment Variable mode. (MAXTOA-1737)