make scheckbuch user behave as previously, but in own file

src/model/user/scheckbuch.rs

@@ -30,16 +30,23 @@ impl ScheckbuchUser {
         user.add_role(db, &scheckbuch).await.unwrap();
 
         // TODO: remove all other `membership_type` roles
+        let new_user = Self::new(db, &user).await.unwrap();
 
-        let new_user = Self::new(db, user).await.unwrap();
+        new_user.notify(db, mail, smtp_pw).await
+    }
 
-        new_user
-            .send_welcome_mail_to_user(db, mail, smtp_pw)
-            .await?;
-        new_user.notify_coxes_about_new_scheckbuch(db).await;
+    pub(crate) async fn notify(
+        &self,
+        db: &SqlitePool,
+        mail: &str,
+        smtp_pw: &str,
+    ) -> Result<(), String> {
+        self.send_welcome_mail_to_user(db, mail, smtp_pw).await?;
+        self.notify_coxes_about_new_scheckbuch(db).await;
 
         Ok(())
     }
+
     async fn send_welcome_mail_to_user(
         &self,
         db: &SqlitePool,