Implement direct mode for Wayland

This patchset is a continuation of Drew DeVault's original MR !141 (closed)

To get this started I am opening the new MR.

What happened since the original patch

• Update Monado window back-end to new comp_target API
• Update to new Wayland drm-lease-unstable-v1 protocol by Xaver Hugl
• Update to new Vulkan header.

TODO:

• Add CMake build

Disclaimer: The CI will fail, since it needs the new Vulkan header.

I tested this on the Index with the sway window manager, it works well.

The patches required in the graphics stack to run this are being tracked in the README here, along with PKGBUILDs for Arch Linux: https://gitlab.freedesktop.org/lubosz/wlxr-pkgbuilds