### 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/routing/allocation/decider/DiskThresholdDecider.java
long freeBytes = 0;
        for (DiskUsage du : usages.values()) {
            totalBytes += du.getTotalBytes();
            freeBytes += du.getFreeBytes();
        }
        return new DiskUsage(node.nodeId(), node.node().getName(), "_na_", totalBytes / usages.size(), freeBytes / usages.size());
    }
    private static final Decision YES_DISABLED = Decision.single(Decision.Type.YES, NAME, "the disk threshold decider is disabled");
    private static final Decision YES_USAGES_UNAVAILABLE = Decision.single(Decision.Type.YES, NAME, "disk usages are unavailable");
    private Decision earlyTerminate(Map<String, DiskUsage> usages) {
        
        if (diskThresholdSettings.isEnabled() == false) {
            return YES_DISABLED;
        }
        
        if (usages.isEmpty()) {
            logger.trace("unable to determine disk usages for disk-aware allocation, allowing allocation");
            return YES_USAGES_UNAVAILABLE;
        }
        return null;
    }
    /**
     * Returns the expected shard size for the given shard or the default value provided if not enough information are available
     * to estimate the shards size.
     */
    public static long getExpectedShardSize(
        ShardRouting shard,
        long defaultValue,
        ClusterInfo clusterInfo,
        SnapshotShardSizeInfo snapshotShardSizeInfo,