### 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/ClusterInfo.java
* Returns the reserved space for each shard on the given node/path pair
     */
    public ReservedSpace getReservedSpace(String nodeId, String dataPath) {
        final ReservedSpace result = reservedSpace.get(new NodeAndPath(nodeId, dataPath));
        return result == null ? ReservedSpace.EMPTY : result;
    }
    /**
     * Method that incorporates the ShardId for the shard into a string that
     * includes a 'p' or 'r' depending on whether the shard is a primary.
     */
    public static String shardIdentifierFromRouting(ShardRouting shardRouting) {
        return shardIdentifierFromRouting(shardRouting.shardId(), shardRouting.primary());
    }
    public static String shardIdentifierFromRouting(ShardId shardId, boolean primary) {
        return shardId.toString() + "[" + (primary ? "p" : "r") + "]";
    }
    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        ClusterInfo that = (ClusterInfo) o;
        return leastAvailableSpaceUsage.equals(that.leastAvailableSpaceUsage)
            && mostAvailableSpaceUsage.equals(that.mostAvailableSpaceUsage)
            && shardSizes.equals(that.shardSizes)
            && shardDataSetSizes.equals(that.shardDataSetSizes)
            && routingToDataPath.equals(that.routingToDataPath)
            && reservedSpace.equals(that.reservedSpace);
    }
    @Override
    public int hashCode() {