### 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
);
            logger.debug(
                "fewer free bytes remaining than the size of all incoming shards: "
                    + "usage {} on node {} including {} bytes of relocations, preventing allocation",
                usage,
                node.nodeId(),
                sizeOfRelocatingShards
            );
            return allocation.decision(
                Decision.NO,
                NAME,
                "the node has fewer free bytes remaining than the total size of all incoming shards: "
                    + "free space [%sB], relocating shards [%sB]",
                freeBytes + sizeOfRelocatingShards,
                sizeOfRelocatingShards
            );
        }
        ByteSizeValue freeBytesValue = new ByteSizeValue(freeBytes);
        if (logger.isTraceEnabled()) {
            logger.trace("node [{}] has {}% used disk", node.nodeId(), usedDiskPercentage);
        }
        
        
        boolean skipLowThresholdChecks = shardRouting.primary()
            && shardRouting.active() == false
            && shardRouting.recoverySource().getType() == RecoverySource.Type.EMPTY_STORE;
        if (freeBytes < diskThresholdSettings.getFreeBytesThresholdLowStage(total).getBytes()) {
            if (skipLowThresholdChecks == false) {
                if (logger.isDebugEnabled()) {
                    logger.debug(