desktop-shell: resize background and panel surfaces on output resize v4

When an output is resized (permanent mode switch), we should also notify the
shell client so that the panel and background fits to the new screen dimensions.

Signed-off-by: David Fort <contact@hardening-consulting.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
2 files changed