This new protocol extension allows clients to specify color
representation metadata. This is orthogonal to color management, which
will be implemented as a separate protocol extension.

Signed-off-by: Sebastian Wick <sebastian.wick@redhat.com>
Co-authored-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Co-authored-by: Simon Ser <contact@emersion.fr>