### Description

Elasticsearch defines the concept of a [feature](https://www.elastic.co/guide/en/elasticsearch/reference/current/get-features-api.html) for the purpose of better managing them when snapshotting/restoring them via the [feature_states field](https://www.elastic.co/guide/en/elasticsearch/reference/current/create-snapshot-api.html#create-snapshot-api-feature-states)

The `shards_availability` health indicator currently diagnoses the condition of indices needing to be [restored from a snapshot](https://github.com/elastic/elasticsearch/blob/main/server/src/main/java/org/elasticsearch/cluster/routing/allocation/ShardsAvailabilityHealthIndicatorService.java#L138) and recommends a [troubleshooting guide](http://ela.st/restore-snapshot)

However, since `8.x` the restore API **must** use `feature_states` instead of specifying systems indices or system data streams as part of the `indices` field.

This proposes the `affected_resources` for the `restore_from_snapshot` diagnosis return the indices that are not part of a `feature` under the `INDICES` type, and a new type `FEATURES`.
e.g. instead of current behaviour
```
"affected_resources": {
  "indices": [
    ".geoip_databases",
    "test_index"
    ]
}
```
we could return:
```
"affected_resources": {
  "indices": [
    "test_index"
   ], 
  "features": [
     "geoip"
  ]
}
```



server/src/main/java/org/elasticsearch/node/Node.java
return client;
    }
    /**
     * Returns the environment of the node
     */
    public Environment getEnvironment() {
        return environment;
    }
    /**
     * Returns the {@link NodeEnvironment} instance of this node
     */
    public NodeEnvironment getNodeEnvironment() {
        return nodeEnvironment;
    }
    /**
     * Start the node. If the node is already started, this method is no-op.
     */
    public Node start() throws NodeValidationException {
        if (lifecycle.moveToStarted() == false) {
            return this;
        }
        logger.info("starting ...");
        pluginLifecycleComponents.forEach(LifecycleComponent::start);
        if (ReadinessService.enabled(environment)) {
            injector.getInstance(ReadinessService.class).start();
        }
        injector.getInstance(MappingUpdatedAction.class).setClient(client);
        injector.getInstance(IndicesService.class).start();
        injector.getInstance(IndicesClusterStateService.class).start();
        injector.getInstance(SnapshotsService.class).start();