Validation Emails

[Tolkie]

We need to send validation emails to newly created users so they can confirm their account.
Users shouldn't be able to access our services without first confirming their account.
The email must constain a confirmation url containing a token.
The token must be stored in a redis instance to ensure its expiration.
We must setup a mail sending feature, via a provider like aws/azure or something else.

[Tolkie]

The users should be able to re-send a validation email given their account is created but not validated, and they enter their email adress.