Email notifications

[aerugo]

Enable email notifications. Work on this has been started in https://github.com/Edgeryders-Participio/realities/tree/email-notify

As we are currently working on Plato as a whole, we should not spend time at this stage on making both Dreams and Realities capable of generating and sending nice emails. Emails from Plato should always have the same format, regardless of if they are triggered by Dreams or Realities. Since orgs currently live in Dreams, it probably makes sense to send the content payload over to Dreams and let the email engine live there.

When triggering an email notification from a responsibility, it should be possible to add and remove org members who get the notification.

[Powersource]

Orgs are stored in the mongo db that both apps have access to. But dreams has better integration towards it and is where we're putting "core" logic atm so I agree we should probably put this there.