[FEATURE] Send an email upon the ban of an IP Address + non blocked requests metric

### What's needed and why?

Bonjour,

- Vous serait-il possible d'ajouter deux fonctions à BunkerWeb : - Une liste sur le même modèle que Block request mais pour les requêtes qui ont été acceptées
- La possibilté que BunkerWeb envoie un email lorsqu'une adresse a été bannie
Merci et bravo pour cet outil très utile.

Here is the English translation:

---

Hello,

* Would it be possible to add two features to BunkerWeb:

* A list, based on the same model as **Block request**, but for requests that have been accepted
* The ability for BunkerWeb to send an email when an address has been banned

Thank you, and congratulations on this very useful tool.

### Implementations ideas (optional)

_No response_

### Code of Conduct

- [x] I agree to follow this project's Code of Conduct

Start by locating the existing Block request list or metric and the ban-handling path in BunkerWeb. Define how accepted requests are collected and how email delivery is configured before implementing either feature. Done means accepted requests are visible in a comparable list and a ban reliably triggers an email.

Written by the indexing model from the issue text.