The SPIRV previously checked in had various issues -- most commonly, it
would use the VertexId and InstanceId builtins rather than the
replacmenet VertexIndex and InstanceIndex builtins required by Vulkan.
Instead of using a small amount of large textured particles, use a large
amount of small monochrome particles.
Which uses a new vulkanexamplebase functionality of creating and
updating a only device visible buffer via a temporary staging buffer.
