Send AUP reminders and expiration email notifications

[rmiccoli]

There is a 4-hour task that checks

• how many days are left before the AUP expires by sending reminder mails
• if the AUP has expired and sends an email notification about the expiration

[sonarcloud[bot]]

Quality Gate failed

Failed conditions
3.3% Duplication on New Code (required ≤ 3%)

See analysis details on SonarCloud