### 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`)
test/framework/src/main/java/org/elasticsearch/transport/AbstractSimpleTransportTestCase.java
}
                @Override
                public void handleException(TransportException exp) {
                    assertThat(exp, instanceOf(ReceiveTimeoutTransportException.class));
                    assertThat(exp.getStackTrace().length, equalTo(0));
                }
            }
        );
        final ExecutionException e = expectThrows(ExecutionException.class, res::get);
        assertThat(e.getCause(), instanceOf(ReceiveTimeoutTransportException.class));
    }
    public void testTimeoutSendExceptionWithDelayedResponse() throws Exception {
        CountDownLatch waitForever = new CountDownLatch(1);
        CountDownLatch doneWaitingForever = new CountDownLatch(1);
        Semaphore inFlight = new Semaphore(Integer.MAX_VALUE);
        serviceA.registerRequestHandler(
            "internal:sayHelloTimeoutDelayedResponse",
            ThreadPool.Names.GENERIC,
            StringMessageRequest::new,
            (request, channel, task) -> {
                String message = request.message;
                inFlight.acquireUninterruptibly();
                try {
                    if ("forever".equals(message)) {
                        waitForever.await();
                    } else {
                        TimeValue sleep = TimeValue.parseTimeValue(message, null, "sleep");
                        Thread.sleep(sleep.millis());
                    }
                    try {