List-* operations should accept also objects as value

[standalone@localhost:9990 /] /subsystem=messaging-activemq/server=default:list-add(name=incoming-interceptors, value={name=foo,module=bar})
{
    "outcome" => "failed",
    "failure-description" => "WFLYCTL0097: Wrong type for value. Expected [STRING] but was OBJECT",
    "rolled-back" => true
}