Add layers and masks cfr Composite map to the VrayCompTex

As per this thread: https://forums.chaos.com/forum/v-ray-for-3ds-max-forums/v-ray-for-3ds-max-general/1229037-haircard-shader

Having layers and masks (similar to the Composite map of 3dsMax) in the VrayCompTex would be a great addition as right now it's quite lacking and creating a more complex setup requires too many nodes. Also because the performance of the default Composite map, according to Lele, isn't ideal, having these options in the VrayCompTex can benefit the performance of more complex setups.