Function spawn_with_result

pub fn spawn_with_result<R, F>(payload: &Payload<Result<R, Error>>, task: F)
where
    R: Clone + Send + 'static,
    F: Future<Output = Result<R>> + Send + 'static,

Spawn an async task that will result in egui redraw upon its completion. Upon the task completion, the supplied Payload will be populated with the task result.