Install vulkan-intel and vulkan-mesa-layers packages when using mhwd (for Intel GPUs)

vulkan-intel and vulkan-mesa-layers are required for intel gpu (when using mesa, which it is by default) for vulkan apps. Without these packages Vulkan apps do not work at all on intel GPU (or have an invisible window like Chromium browsers). This will become a huge issue when Chromium defaults to using Vulkan.

I’m requesting to install these packages when installing video driver for intel via mhwd.