### Description

The `sendRequest` method is asynchronous and notifies a 
`TransportResponseHandler` when it completes the excecution
(successfully or unsuccessfully). 

When opening the connection we only catch `NodeNotConnectedException`
( https://github.com/elastic/elasticsearch/blob/main/server/src/main/java/org/elasticsearch/transport/TransportService.java#L719 ) which is currently fine as no implementations
throw other type of exception however, it'd be best to catch `Exception` here
so the `handler` gets notified of potential exceptions (as opposed to the caller
having to `try/catch` the call to `sendRequest`)
server/src/main/java/org/elasticsearch/transport/TransportService.java
@Nullable ClusterSettings clusterSettings,
        Set<String> taskHeaders
    ) {
        this(settings, transport, threadPool, transportInterceptor, localNodeFactory, clusterSettings, taskHeaders, Tracer.NOOP);
    }
    /**
     * Build the service.
     *
     * @param clusterSettings if non null, the {@linkplain TransportService} will register with the {@link ClusterSettings} for settings
     *    updates for {@link TransportSettings#TRACE_LOG_EXCLUDE_SETTING} and {@link TransportSettings#TRACE_LOG_INCLUDE_SETTING}.
     */
    public TransportService(
        Settings settings,
        Transport transport,
        ThreadPool threadPool,
        TransportInterceptor transportInterceptor,
        Function<BoundTransportAddress, DiscoveryNode> localNodeFactory,
        @Nullable ClusterSettings clusterSettings,
        TaskManager taskManager,
        Tracer tracer
    ) {
        this(
            settings,
            transport,
            threadPool,
            transportInterceptor,
            localNodeFactory,
            clusterSettings,
            new ClusterConnectionManager(settings, transport, threadPool.getThreadContext()),
            taskManager,