refactor: change global __get return form source() to all() (#382)

not BC but improvement `source()` union of `all()`

src/System/Http/Request.php

@@ -610,7 +610,7 @@ public function offsetUnset($offset): void
      */
     public function __get($key)
     {
-        return $this->source()->get($key);
+        return $this->all()[$key] ?? null;
     }
 
     /**