### 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
final List<TracerPlugin> tracerPlugins = pluginsService.filterPlugins(TracerPlugin.class);
        if (tracerPlugins.size() > 1) {
            throw new IllegalStateException("A single TracerPlugin was expected but got: " + tracerPlugins);
        }
        return tracerPlugins.isEmpty() ? Tracer.NOOP : tracerPlugins.get(0).getTracer(settings);
    }
    private HealthService createHealthService(
        ClusterService clusterService,
        ClusterModule clusterModule,
        CoordinationDiagnosticsService coordinationDiagnosticsService,
        ThreadPool threadPool
    ) {
        List<HealthIndicatorService> preflightHealthIndicatorServices = Collections.singletonList(
            new StableMasterHealthIndicatorService(coordinationDiagnosticsService, clusterService)
        );
        var serverHealthIndicatorServices = new ArrayList<>(
            List.of(
                new RepositoryIntegrityHealthIndicatorService(clusterService),
                new ShardsAvailabilityHealthIndicatorService(clusterService, clusterModule.getAllocationService())
            )
        );
        serverHealthIndicatorServices.add(new DiskHealthIndicatorService(clusterService));
        var pluginHealthIndicatorServices = pluginsService.filterPlugins(HealthPlugin.class)
            .stream()
            .flatMap(plugin -> plugin.getHealthIndicatorServices().stream())
            .toList();
        return new HealthService(
            preflightHealthIndicatorServices,
            concatLists(serverHealthIndicatorServices, pluginHealthIndicatorServices),
            threadPool