### 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
forciblyCast(injector.getInstance(new Key<Map<ActionType, TransportAction>>() {
                }));
            client.initialize(
                actions,
                transportService.getTaskManager(),
                () -> clusterService.localNode().getId(),
                transportService.getLocalNodeConnection(),
                transportService.getRemoteClusterService(),
                namedWriteableRegistry
            );
            this.namedWriteableRegistry = namedWriteableRegistry;
            this.namedXContentRegistry = xContentRegistry;
            logger.debug("initializing HTTP handlers ...");
            actionModule.initRestHandlers(() -> clusterService.state().nodesIfRecovered());
            logger.info("initialized");
            success = true;
        } catch (IOException ex) {
            throw new ElasticsearchException("failed to bind service", ex);
        } finally {
            if (success == false) {
                IOUtils.closeWhileHandlingException(resourcesToClose);
            }
        }
    }
    /**
     * If the JVM was started with the Elastic APM agent and a config file argument was specified, then
     * delete the config file. The agent only reads it once, when supplied in this fashion, and it
     * may contain a secret token.
     * <p>
     * Public for testing only