protocol: add invalid_size error to wl_surface

This allows the compositor to send an error when the client submits a buffer
whose size is not divisible by the buffer scale. Previously, the protocol said
it was a client error but didn't specify any error code.

Signed-off-by: Simon Ser <contact@emersion.fr>
Closes: https://gitlab.freedesktop.org/wayland/wayland/issues/145