util/vulkan: Add vk_outarray (v2)

util/vulkan: Add vk_outarray (v2)

This is a wrapper for a Vulkan output array. A Vulkan output array is
one that follows the convention of the parameters to
vkGetPhysicalDeviceQueueFamilyProperties().

v2: Replace vk_outarray_is_incomplete() with vk_outarray_status(). For
    Jason.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>