libvulkan: Implement EXT_swapchain_maintenance1

The loader now implements EXT_swapchain_maintenance1 and
EXT_surface_maintenance1, which fix assorted issues with the original
swapchain extension. Our implementation of EXT_swapchain_maintenance1 is
conditional on the underlying driver having support for importing
sync fds as external fences (which requires Vulkan 1.1 + support for
VK_KHR_external_fence_fd).

Bug: b/255376900

Change-Id: I72ce770a7296e4e97cccf13bad420aa5a1001a6a