message: Add resolve_atom constant
diff: @@ -116,6 +116,9 @@ using get_atom = atom_constant<atom("get")>;
  /// Used for request operations.
  using put_atom = atom_constant<atom("put")>;
  +/// Used for signalizing resolved paths.
  +using resolve_atom = atom_constant<atom("resolve")>;
  +
  /// Used for signalizing updates, e.g., in a key-value store.
  using update_atom = atom_constant<atom("update")>;
  