### 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/InternalClusterInfoService.java
ActionListener<ClusterInfo> getListener() {
            return ActionListener.wrap(() -> {
                if (shouldRefresh()) {
                    threadPool.scheduleUnlessShuttingDown(updateFrequency, ThreadPool.Names.SAME, () -> {
                        if (shouldRefresh()) {
                            refreshAsync(getListener());
                        }
                    });
                }
            });
        }
        private boolean shouldRefresh() {
            synchronized (mutex) {
                return refreshScheduler == this;
            }
        }
    }
    @Override