### Description

It should be enough to have ShardId + nodeId key in `routingToDataPath` to find the necessary data path. 
Changing the key would allow us to minimize the size of ClusterInfo size and find the data path when shard changes its status.

`ClusterInfo` might be sent over the wire when cluster allocation explain is executed with `includeDiskInfo=true`.
ShardRouting -> ShardId + nodeId conversion is trivial. The oposit would require additional information that could be faked.

Current key is also used in here:
https://github.com/elastic/elasticsearch/blob/9ebbe1c62bf0157d332f20f392544a1921a710df/server/src/main/java/org/elasticsearch/cluster/ClusterInfo.java#L149-L154
where it produces a string with ShardRouting#shortSummary that is excessive and might be simplified to ShardId + nodeId as well
server/src/main/java/org/elasticsearch/cluster/InternalClusterInfoService.java
dataPathByShardRoutingBuilder,
                                    reservedSpaceBuilders
                                );
                                final Map<ClusterInfo.NodeAndPath, ClusterInfo.ReservedSpace> rsrvdSpace = new HashMap<>();
                                reservedSpaceBuilders.forEach((nodeAndPath, builder) -> rsrvdSpace.put(nodeAndPath, builder.build()));
                                indicesStatsSummary = new IndicesStatsSummary(
                                    Map.copyOf(shardSizeByIdentifierBuilder),
                                    Map.copyOf(shardDataSetSizeBuilder),
                                    Map.copyOf(dataPathByShardRoutingBuilder),
                                    Map.copyOf(rsrvdSpace)
                                );
                            }
                            @Override
                            public void onFailure(Exception e) {
                                if (e instanceof ClusterBlockException) {
                                    logger.trace("failed to retrieve indices stats", e);
                                } else {
                                    logger.warn("failed to retrieve indices stats", e);
                                }
                                indicesStatsSummary = IndicesStatsSummary.EMPTY;
                            }
                        }, this::onStatsProcessed),
                        false
                    )
                );
        }
        private void fetchNodeStats() {
            final NodesStatsRequest nodesStatsRequest = new NodesStatsRequest("data:true");
            nodesStatsRequest.clear();
            nodesStatsRequest.addMetric(NodesStatsRequest.Metric.FS.metricName());