ch: virCHProcessEvent() vm shutdown event handler fix

ch: virCHProcessEvent() vm shutdown event handler fix

When the domain shutdown was executed from virsh, only the VM
process (a child of the CH monitor) was terminated. Since we assume
only one VM per monitor, the monitor process should also be
terminated.

Modified the VM shutdown event handler to match the VMM shutdown
behavior, ensuring the VM monitor stops along with the VM. Also
updated the virCHEventStopProcess job type, as it only destroys the
domain rather than modifying anything.

Signed-off-by: Kirill Shchetiniuk <kshcheti@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>