Lavapipe ICD component

This directory defines two artifacts:

• A shared library ICD which provides a Lavapipe-based software Vulkan implementation
  • Currently this is a stub implementation, see https://fxbug.dev/42075795
• A component which makes this ICD available to the Fuchsia Vulkan loader service, and therefore to Vulkan client apps.
  • The Vulkan Loader RFC-0205 describes how the parts fit together.