### 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
import org.elasticsearch.plugins.AnalysisPlugin;
import org.elasticsearch.plugins.CircuitBreakerPlugin;
import org.elasticsearch.plugins.ClusterPlugin;
import org.elasticsearch.plugins.DiscoveryPlugin;
import org.elasticsearch.plugins.EnginePlugin;
import org.elasticsearch.plugins.HealthPlugin;
import org.elasticsearch.plugins.IndexStorePlugin;
import org.elasticsearch.plugins.IngestPlugin;
import org.elasticsearch.plugins.MapperPlugin;
import org.elasticsearch.plugins.MetadataUpgrader;
import org.elasticsearch.plugins.NetworkPlugin;
import org.elasticsearch.plugins.PersistentTaskPlugin;
import org.elasticsearch.plugins.Plugin;
import org.elasticsearch.plugins.PluginsService;
import org.elasticsearch.plugins.RecoveryPlannerPlugin;
import org.elasticsearch.plugins.RepositoryPlugin;
import org.elasticsearch.plugins.ScriptPlugin;
import org.elasticsearch.plugins.SearchPlugin;
import org.elasticsearch.plugins.ShutdownAwarePlugin;
import org.elasticsearch.plugins.SystemIndexPlugin;
import org.elasticsearch.plugins.TracerPlugin;
import org.elasticsearch.readiness.ReadinessService;
import org.elasticsearch.repositories.RepositoriesModule;
import org.elasticsearch.repositories.RepositoriesService;
import org.elasticsearch.reservedstate.ReservedClusterStateHandler;
import org.elasticsearch.reservedstate.ReservedClusterStateHandlerProvider;
import org.elasticsearch.reservedstate.action.ReservedClusterSettingsAction;
import org.elasticsearch.reservedstate.service.FileSettingsService;
import org.elasticsearch.rest.RestController;
import org.elasticsearch.script.ScriptContext;