### 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
Index anotherIndex = new Index(anotherIndexName, "5678");
        Metadata metadata = Metadata.builder()
            .put(
                IndexMetadata.builder(mainIndexName)
                    .settings(
                        settings(Version.CURRENT).put("index.uuid", "1234")
                            .put(INDEX_STORE_TYPE_SETTING.getKey(), SEARCHABLE_SNAPSHOT_STORE_TYPE)
                    )
                    .numberOfShards(3)
                    .numberOfReplicas(1)
            )
            .put(
                IndexMetadata.builder(anotherIndexName)
                    .settings(settings(Version.CURRENT).put("index.uuid", "5678"))
                    .numberOfShards(1)
                    .numberOfReplicas(1)
            )
            .build();
        String nodeId = "node1";
        String anotherNodeId = "another_node";
        List<ShardRouting> shards = new ArrayList<>();
        int anotherNodeShardCounter = 0;
        int nodeShardCounter = 0;
        Map<String, Long> initializingShardSizes = new HashMap<>();
        for (int i = 1; i <= 3; i++) {
            int expectedSize = 10 * i;
            shards.add(createShard(index, nodeId, nodeShardCounter++, expectedSize));
            if (randomBoolean()) {
                ShardRouting initializingShard = ShardRoutingHelper.initialize(
                    ShardRouting.newUnassigned(