### 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/test/java/org/elasticsearch/cluster/routing/allocation/decider/DiskThresholdDeciderUnitTests.java
shards.stream()
                            .filter(s -> s.getIndexName().equals(mainIndexName))
                            .reduce(IndexRoutingTable.builder(index), IndexRoutingTable.Builder::addShard, (a, b) -> a)
                    )
                    .add(
                        shards.stream()
                            .filter(s -> s.getIndexName().equals(anotherIndexName))
                            .reduce(IndexRoutingTable.builder(anotherIndex), IndexRoutingTable.Builder::addShard, (a, b) -> a)
                    )
                    .build()
            )
            .nodes(DiscoveryNodes.builder().add(node).add(anotherNode).build())
            .build();
        RoutingAllocation allocation = new RoutingAllocation(
            null,
            clusterState,
            new DevNullClusterInfo(Map.of(), Map.of(), initializingShardSizes),
            null,
            0
        );
        long sizeOfUnaccountedShards = sizeOfUnaccountedShards(
            allocation,
            RoutingNodesHelper.routingNode(nodeId, node, shards.toArray(ShardRouting[]::new)),
            false,
            "/dev/null"
        );
        assertEquals(60L + initializingShardSizes.values().stream().mapToLong(Long::longValue).sum(), sizeOfUnaccountedShards);
    }
    private ShardRouting createShard(Index index, String nodeId, int i, int expectedSize) {
        var unassigned = ShardRouting.newUnassigned(