### 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/test/java/org/elasticsearch/cluster/routing/allocation/ShardsAvailabilityHealthIndicatorServiceTests.java
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorService.ACTION_MIGRATE_TIERS_AWAY_FROM_INCLUDE_DATA_LOOKUP;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorService.ACTION_MIGRATE_TIERS_AWAY_FROM_REQUIRE_DATA_LOOKUP;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorService.ACTION_RESTORE_FROM_SNAPSHOT;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorService.DIAGNOSIS_WAIT_FOR_OR_FIX_DELAYED_SHARDS;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorService.NAME;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorServiceTests.ShardState.AVAILABLE;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorServiceTests.ShardState.INITIALIZING;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorServiceTests.ShardState.RESTARTING;
import static org.elasticsearch.cluster.routing.allocation.ShardsAvailabilityHealthIndicatorServiceTests.ShardState.UNAVAILABLE;
import static org.elasticsearch.cluster.routing.allocation.decider.ShardsLimitAllocationDecider.CLUSTER_TOTAL_SHARDS_PER_NODE_SETTING;
import static org.elasticsearch.common.util.CollectionUtils.concatLists;
import static org.elasticsearch.core.TimeValue.timeValueSeconds;
import static org.elasticsearch.health.Diagnosis.Resource.Type.INDEX;
import static org.elasticsearch.health.HealthStatus.GREEN;
import static org.elasticsearch.health.HealthStatus.RED;
import static org.elasticsearch.health.HealthStatus.YELLOW;
import static org.hamcrest.Matchers.contains;
import static org.hamcrest.Matchers.containsInAnyOrder;
import static org.hamcrest.Matchers.equalTo;
import static org.hamcrest.Matchers.hasSize;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;
public class ShardsAvailabilityHealthIndicatorServiceTests extends ESTestCase {
    public void testShouldBeGreenWhenAllPrimariesAndReplicasAreStarted() {
        var clusterState = createClusterStateWith(
            List.of(
                index("replicated-index", new ShardAllocation(randomNodeId(), AVAILABLE), new ShardAllocation(randomNodeId(), AVAILABLE)),
                index("unreplicated-index", new ShardAllocation(randomNodeId(), AVAILABLE))
            ),