### 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
public void writeTo(StreamOutput out) throws IOException {
            super.writeTo(out);
            if (out.getVersion().onOrAfter(version1)) {
                out.writeInt(value2);
            }
        }
    }
    public void testVersionFrom0to1() throws Exception {
        serviceB.registerRequestHandler("internal:version", ThreadPool.Names.SAME, Version1Request::new, (request, channel, task) -> {
            assertThat(request.value1, equalTo(1));
            assertThat(request.value2, equalTo(0)); 
            Version1Response response = new Version1Response(1, 2);
            channel.sendResponse(response);
            assertEquals(version0, channel.getVersion());
        });
        Version0Request version0Request = new Version0Request();
        version0Request.value1 = 1;
        Version0Response version0Response = submitRequest(
            serviceA,
            nodeB,
            "internal:version",
            version0Request,
            new TransportResponseHandler<Version0Response>() {
                @Override
                public Version0Response read(StreamInput in) throws IOException {
                    return new Version0Response(in);
                }
                @Override
                public void handleResponse(Version0Response response) {
                    assertThat(response.value1, equalTo(1));