EGL: Implement EGL_EXT_device_drm and EXT_device_drm_render_node These extensions are needed by Exo for zwp_linux_dmabuf v4 support. Add the needed infrastructure to the EGL backend to support device queries and expose the extensions there. In the future we will want to support the extensions on Vulkan as well, however unfortunately this is not trivial, so leave it out for now. Bug: angleproject:7686 Change-Id: I0a54bf58dbaa9e87c8baac760cb9ac9027fea4c2 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3964272 Reviewed-by: Jonah Ryan-Davis <jonahr@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Jonah Ryan-Davis <jonahr@google.com>