Provide access to signal parameters in SignalTransition::onTriggered

In the following example, assume mousePressed includes a pos parameter

SignalTransition {
    signal: mousePressed
    guard: pos.x > 15
    onTriggered: console.log(pos.x)
}

In this example, the guard clause has access to the pos parameter, but onTriggered does not (console.log(pos.x) will fail). It would be helpful to have this information available in onTriggered.