ch: Enable callbacks for ch domain events

Enable callbacks for define, undefine, started, booted, stopped,
destroyed events of ch guests.

Signed-off-by: Praveen K Paladugu <praveenkpaladugu@gmail.com>
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>