implement community basics

src/PersistentData/Model/User.php

@@ -171,6 +171,11 @@ class User extends Model implements IUser
         return $this->nickname ?: $this->fullName;
     }
 
+    public function getFullDisplayName(): string
+    {
+        return $this->nickname ? $this->nickname . ' (' . $this->fullName . ')' : $this->fullName;
+    }
+
     public function checkPassword(string $password): bool
     {
         if ($this->password === null) {