### 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/cluster/coordination/CoordinationDiagnosticsService.java
@Nullable String remoteExceptionStackTrace,
        @Nullable Map<String, String> nodeToClusterFormationDescriptionMap
    ) implements Writeable {
        public CoordinationDiagnosticsDetails(
            DiscoveryNode currentMaster,
            List<DiscoveryNode> recentMasters,
            Exception remoteException,
            Map<String, String> nodeToClusterFormationDescriptionMap
        ) {
            this(
                currentMaster,
                recentMasters,
                remoteException == null ? null : remoteException.getMessage(),
                getStackTrace(remoteException),
                nodeToClusterFormationDescriptionMap
            );
        }
        public CoordinationDiagnosticsDetails(StreamInput in) throws IOException {
            this(
                readCurrentMaster(in),
                readRecentMasters(in),
                in.readOptionalString(),
                in.readOptionalString(),
                readClusterFormationStates(in)
            );
        }
        private static DiscoveryNode readCurrentMaster(StreamInput in) throws IOException {
            boolean hasCurrentMaster = in.readBoolean();
            DiscoveryNode currentMaster;
            if (hasCurrentMaster) {