### 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
clusterService,
                repositoryService,
                clusterModule.getAllocationService(),
                metadataCreateIndexService,
                clusterModule.getMetadataDeleteIndexService(),
                indexMetadataVerifier,
                shardLimitValidator,
                systemIndices,
                indicesService,
                fileSettingsService,
                threadPool
            );
            final DiskThresholdMonitor diskThresholdMonitor = new DiskThresholdMonitor(
                settings,
                clusterService::state,
                clusterService.getClusterSettings(),
                client,
                threadPool::relativeTimeInMillis,
                rerouteService
            );
            clusterInfoService.addListener(diskThresholdMonitor::onNewInfo);
            final DiscoveryModule discoveryModule = new DiscoveryModule(
                settings,
                transportService,
                client,
                namedWriteableRegistry,
                networkService,
                clusterService.getMasterService(),
                clusterService.getClusterApplierService(),
                clusterService.getClusterSettings(),