wayland-ivi-extension: Added ivi-id-agent by mtey

As explained in further discussions, the simple-id-agent
is a basic example for reference. This commit adds the
ivi-id-agent [1]. It is still a reference implementation
but already offers more features (like configurations)
that should be desirable for AGL.

[1] https://github.com/mtey/wayland-ivi-extension/commits/xdg_support_ivi_id_agent

Change-Id: I041b81b480be8fd49fded9d9c9824a0dbb3b568f
Signed-off-by: Michael Teyfel <mteyfel@de.adit-jv.com>