Don't use internal wayland based input context

Signed-off-by: Simon Busch <morphis@gravedo.de>
Try one more option to get a valid EGLDisplay instance

Upstream-Status: Inappropiate (configuration)

Signed-off-by: Simon Busch <morphis@gravedo.de>
Implement nativeResourceForContext() to get EGL context

Make it possible to get the EGL context from the QOpenGLContext handle.