feat(api): can grant external user (via email)

- add possibility to grant an external user.
    - route /api/users/{id} added (rate limited for security)
    - security: start route limitation for external users
        ex: they must not browse /api/users/{id} nor addressbook

src/interfaces/middleware/mod.rs

@@ -4,3 +4,4 @@ pub mod csrf;
 pub mod rate_limit;
 pub mod trace_span;
 pub mod trusted_proxy;
+pub mod user;