Allocation Explain API to report Node Data Tier

[stefnestor]

Description

Would y'all kindly consider adding node_roles to the Allocation Explain API response JSON same as it currently reports node_attributes under both current_node and node_allocation_decisions?

Highlight current in red (to keep) and request in green (to add):

{
  "index": "test-00001",
  "shard": 1,
  "primary": false,
  "current_state": "started",
  "current_node": {
    "id": "asdf",
    "name": "asdf",
    "transport_address": "10.10.10.10:9300",
-    "attributes": {
-      "xpack.installed": "true",
-      "data": "hot",
-      "zone": "zone1"
-    },
+     "roles": [
+       "data_hot", 
+       "data_content"
+    ]
  },
  "can_remain_on_current_node": "no",
  "can_remain_decisions": [{
      "decider": "data_tier",
      "decision": "NO",
      "explanation": "index has a preference for tiers [data_cold,data_warm,data_hot] and node does not meet the required [data_cold] tier"
  }],
  "can_move_to_other_node": "no",
  "move_explanation": "This shard may not remain on its current node, but Elasticsearch isn't allowed to move it to another node. Choose a node to which you expect this shard to be allocated, find this node in the node-by-node explanation, and address the reasons which prevent Elasticsearch from allocating this shard there.",
  "node_allocation_decisions": [
    {
      "node_id": "qwer",
      "node_name": "qwer",
      "transport_address": "10.10.10.11:9300",
-      "node_attributes": {
-        "xpack.installed": "true",
-        "data": "warm",
-        "zone": "zone2"
-      },
+      "roles": [
+         "data_warm"
+     ],
      "node_decision": "no",
      "weight_ranking": 1,
      "deciders": [
        {
          "decider": "data_tier",
          "decision": "NO",
          "explanation": "index has a preference for tiers [data_cold,data_warm,data_hot] and node does not meet the required [data_cold] tier"
        }
      ]
    }
  ]
}

[elasticsearchmachine]

Pinging @elastic/es-distributed (Team:Distributed)

[DiannaHohensee]

Closed by #98550