### 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
+ "usage {} on node {} including {} bytes of relocations, shard cannot remain",
                usage,
                node.nodeId(),
                sizeOfRelocatingShards
            );
            return allocation.decision(
                Decision.NO,
                NAME,
                "the shard cannot remain on this node because the node has fewer free bytes remaining than the total size of all "
                    + "incoming shards: free space [%s], relocating shards [%s]",
                freeBytes + sizeOfRelocatingShards,
                sizeOfRelocatingShards
            );
        }
        if (freeBytes < diskThresholdSettings.getFreeBytesThresholdHighStage(total).getBytes()) {
            if (logger.isDebugEnabled()) {
                logger.debug(
                    "node {} is over the high watermark setting [{}], having less than the required {} free space "
                        + "(actual free: {}, actual used: {}), shard cannot remain",
                    node.nodeId(),
                    diskThresholdSettings.describeHighThreshold(total, false),
                    diskThresholdSettings.getFreeBytesThresholdHighStage(total),
                    freeBytes,
                    Strings.format1Decimals(usedDiskPercentage, "%")
                );
            }
            return allocation.decision(
                Decision.NO,
                NAME,
                "the shard cannot remain on this node because it is above the high watermark cluster setting [%s] "