Do not flush in the repository

[lyrixx]

ATM, the generated code is:

    public function add(Message $entity, bool $flush = true): void
    {
        $this->_em->persist($entity);
        if ($flush) {
            $this->_em->flush();
        }
    }

This is a bad idea:

• it's confusing: one may thing it will flush only the new message (it's not!)
• flush should be done in the most outside layer of the application (controller, command, message handler) to avoid flushing invalid data

[nicolas-grekas]

I agree. I'd vote for removing this function personally. Same for save()

[weaverryan]

Yea, I think we had decided to remove all of those methods in the repo - I just haven’t had time to do it. PR welcome!