allow returning RestAction as command response

Author: kaleidox

src/main/java/org/comroid/commands/impl/discord/JdaCommandAdapter.java

@@ -268,6 +268,7 @@ private CompletableFuture<?> handleResponse(JdaCommandAdapter.MessageSender hook
                 if (embedFinalizer != null) embed = embedFinalizer.apply(embed, user);
                 yield hook.send(embed.build());
             }
+            case RestAction<?> action -> action.submit();
             default -> hook.send(String.valueOf(response));
         });
     }