support aws service discovery cloud map

[ashraf-revo]

i think it will be good idea if we support aws service discovery cloud map like k8s discovery ,eureka service discovery
i have tried this and it work fine
`public class EcsReactiveDiscoveryClient implements ReactiveDiscoveryClient {
private final EcsDiscoveryProperties properties;
private final AWSServiceDiscoveryAsync discoveryAsync;
private final static String INSTANCE_IPV4 = "AWS_INSTANCE_IPV4";

public EcsReactiveDiscoveryClient(EcsDiscoveryProperties properties, AWSServiceDiscoveryAsync discoveryAsync) {
    this.properties = properties;
    this.discoveryAsync = discoveryAsync;
}

@Override
public String description() {
    return "ecs discovery client";
}

@Override
public Flux<ServiceInstance> getInstances(String serviceId) {
    DiscoverInstancesRequest request = new DiscoverInstancesRequest();
    request.setNamespaceName(properties.getNamespace());
    request.setServiceName(serviceId);
    List<HttpInstanceSummary> instances = discoveryAsync.discoverInstances(request).getInstances();
    log.info("getting " + instances.size() + " services for " + serviceId);
    List<DefaultServiceInstance> discoveredServiceInstances = instances.stream().map(instance -> {
        String host = instance.getAttributes().get(INSTANCE_IPV4);
        return new DefaultServiceInstance(instance.getInstanceId(), serviceId, host, 80, false, instance.getAttributes());
    }).collect(Collectors.toList());
    return Flux.fromIterable(discoveredServiceInstances);
}

@Override
public Flux<String> getServices() {
    ListServicesRequest listServicesRequest = new ListServicesRequest();
    ListServicesResult listServicesResult = discoveryAsync.listServices(listServicesRequest);
    log.info("getting all services");
    List<String> discoveredServices = listServicesResult.getServices().stream().map(ServiceSummary::getName)
            .collect(Collectors.toList());
    log.info("got those services " + discoveredServices);
    return Flux.fromIterable(discoveredServices);
}

}`