Bug 3150: (follow-up) Send list and cart emails immediately again

Bug 3150: (follow-up) Send list and cart emails immediately again

With this patch set the cart and list emails are sent via
the message_queue instead of bypassing it and being sent
immediately. This patch keeps them in message_queue, but
also sends them immediately, restoring the previous behavior.

Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>