feat: use Oban jobs for email queue #9
Description
Think and implement a solution for the queuing of emails.
Take this situation as an example:
Every year, when the semester starts, we have to send an email to all the students in the system notifying them that the schedules are available. This can turn into a problem considering that our course has hundreds of students.
By queuing these emails we can send batches of them gradually, avoiding congestion in the email sending provider.