Add Wayland EGL-based NSOpenGLContext and PixelFormat backend

[DMJC]

Motivation

• Provide OpenGL support for the Wayland backend by implementing an EGL-based NSOpenGLContext and NSOpenGLPixelFormat to allow apps to create GL-backed views on Wayland.
• Integrate GL support into the Wayland server window lifecycle so windows can be marked as using OpenGL and avoid Cairo flushes for GL-backed surfaces.
• Expose the new GL classes to the display server so higher-level code can instantiate GL contexts and pixel formats for Wayland.

Description

• Add Headers/wayland/WaylandOpenGL.h declaring WaylandGLContext and WaylandGLPixelFormat classes and state needed for EGL and wl_egl_window management.
• Implement WaylandGLContext in Source/wayland/WaylandGLContext.m providing EGL display/context/surface creation, makeCurrentContext, flushBuffer, setView: binding to Wayland struct window, and lifecycle/resize handling.
• Implement WaylandGLPixelFormat in Source/wayland/WaylandGLPixelFormat.m to translate NSOpenGLPixelFormatAttribute lists into an EGLConfig via eglChooseConfig.
• Integrate with server code in Source/wayland/WaylandServer.m by including the new header, returning get_window_with_id from windowDevice:, adding glContextClass and glPixelFormatClass accessors, initializing a usesOpenGL flag on window creation, and skipping Cairo flushes for GL-backed windows.
• Update Source/wayland/GNUmakefile to compile the new Objective-C sources and add link flags -lEGL -lwayland-egl.

Testing

• Built the Wayland subproject via the updated GNUmakefile using the normal make flow, and the Wayland backend compiled successfully (no compilation errors reported).
• Ran a build of the overall project that includes the Wayland backend and confirmed successful link of -lEGL and -lwayland-egl libraries.
• No automated unit tests were added for GL behavior in this change set.

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Codex Task