### 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
}
    /**
     * This method checks whether each master eligible node has discovered each of the other master eligible nodes. For the sake of this
     * method, a discovery problem is when the foundPeers of any ClusterFormationState on any node we have that information for does not
     * contain all of the nodes in the local coordinator.getFoundPeers().
     * @param masterEligibleNodes The collection of all master eligible nodes
     * @param nodeToClusterFormationStateMap A map of each master node to its ClusterFormationState
     * @return true if there are discovery problems, false otherwise
     */
    static boolean anyNodeInClusterReportsDiscoveryProblems(
        Collection<DiscoveryNode> masterEligibleNodes,
        Map<DiscoveryNode, ClusterFormationFailureHelper.ClusterFormationState> nodeToClusterFormationStateMap
    ) {
        Map<DiscoveryNode, Collection<DiscoveryNode>> nodesNotDiscoveredMap = new HashMap<>();
        for (Map.Entry<DiscoveryNode, ClusterFormationFailureHelper.ClusterFormationState> entry : nodeToClusterFormationStateMap
            .entrySet()) {
            Set<DiscoveryNode> foundPeersOnNode = new HashSet<>(entry.getValue().foundPeers());
            if (foundPeersOnNode.containsAll(masterEligibleNodes) == false) {
                Collection<DiscoveryNode> nodesNotDiscovered = masterEligibleNodes.stream()
                    .filter(node -> foundPeersOnNode.contains(node) == false)
                    .toList();
                nodesNotDiscoveredMap.put(entry.getKey(), nodesNotDiscovered);
            }
        }
        if (nodesNotDiscoveredMap.isEmpty()) {
            return false;
        } else {
            String nodeDiscoveryProblemsMessage = nodesNotDiscoveredMap.entrySet()
                .stream()
                .map(