WIP: multi-backend: VNC backend GL renderer support
Based on !578 (merged) and !879 (closed), allow to load the VNC backend as a secondary backend to a DRM or Wayland backend using the GL renderer.
Adds GL renderer support to the VNC backend.
Based on !578 (merged) and !879 (closed), allow to load the VNC backend as a secondary backend to a DRM or Wayland backend using the GL renderer.
Adds GL renderer support to the VNC backend.