### 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/test/java/org/elasticsearch/cluster/routing/allocation/decider/DiskThresholdDeciderUnitTests.java
mostAvailableUsage,
            shardSizes,
            Map.of(),
            shardRoutingMap,
            Map.of()
        );
        RoutingAllocation allocation = new RoutingAllocation(
            new AllocationDeciders(Collections.singleton(decider)),
            clusterState,
            clusterInfo,
            null,
            System.nanoTime()
        );
        allocation.debugDecision(true);
        Decision decision = decider.canRemain(indexMetadata, test_0, RoutingNodesHelper.routingNode("node_0", node_0), allocation);
        assertEquals(Decision.Type.YES, decision.type());
        assertThat(
            ((Decision.Single) decision).getExplanation(),
            containsString(
                "there is enough disk on this node for the shard to remain, free: ["
                    + ByteSizeValue.ofBytes(exactFreeSpaceForHighWatermark)
                    + "]"
            )
        );
        decision = decider.canRemain(indexMetadata, test_1, RoutingNodesHelper.routingNode("node_1", node_1), allocation);
        assertEquals(Decision.Type.NO, decision.type());
        assertThat(
            ((Decision.Single) decision).getExplanation(),
            containsString(
                "the shard cannot remain on this node because it is above the high watermark cluster setting "