### 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
nodeA,
                "internal:sayHello",
                new StringMessageRequest("moshe"),
                new TransportResponseHandler<>() {
                    @Override
                    public StringMessageResponse read(StreamInput in) throws IOException {
                        return new StringMessageResponse(in);
                    }
                    @Override
                    public String executor() {
                        return ThreadPool.Names.GENERIC;
                    }
                    @Override
                    public void handleResponse(StringMessageResponse response) {
                        assertThat("hello moshe", equalTo(response.message));
                    }
                    @Override
                    public void handleException(TransportException exp) {
                        logger.error("Unexpected failure", exp);
                        fail("got exception instead of a response: " + exp.getMessage());
                    }
                }
            );
            StringMessageResponse message = res.get();
            assertThat("hello moshe", equalTo(message.message));
        }
    }
    public void testIndexingDataCompression() throws Exception {
        try (MockTransportService serviceC = buildService("TS_C", CURRENT_VERSION, Settings.EMPTY)) {
            String component = "cccccccccooooooooooooooommmmmmmmmmmppppppppppprrrrrrrreeeeeeeeeessssssssiiiiiiiiiibbbbbbbbllllllllleeeeee";