EventSourcedOrchestratingAggregate added

[idugalic]

Orchestrating Event Sourced Aggregate - composing deciders and sagas in single transaction

It uses a Decider and Saga to compute new events based on the current/stored events and the new command.
If the decider is combined from many deciders via the combine function, a saga could be used to react to new events and send new commands to the decider recursively in a single transaction!

#[tokio::test]
async fn orchestrated_event_sourced_aggregate_test() {
    let combined_decider = order_decider()
        .combine(shipment_decider()) // Decider<Sum<OrderCommand, ShipmentCommand>, (OrderState, ShipmentState), Sum<OrderEvent, ShipmentEvent>>
        .map_command(&command_from_sum) // Decider<Command, (OrderState, ShipmentState), Sum<OrderEvent, ShipmentEvent>>
        .map_event(&event_from_sum, &sum_to_event); // Decider<Command, (OrderState, ShipmentState), Event>
    let combined_saga = order_saga()
        .combine(shipment_saga())
        .map_action(&sum_to_command)
        .map_action_result(&event_from_sum);
    let repository = InMemoryEventRepository::new();
    let aggregate = Arc::new(EventSourcedOrchestratingAggregate::new(
        repository,
        combined_decider.map_error(&|()| AggregateError::DomainError("Decider error".to_string())),
        combined_saga,
    ));
...

Check the aggregate_combined_test.rs for more details.