### 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/cluster/routing/allocation/ShardsAvailabilityHealthIndicatorService.java
)
        );
    public static final Diagnosis.Definition ACTION_MIGRATE_TIERS_AWAY_FROM_INCLUDE_DATA = new Diagnosis.Definition(
        NAME,
        "migrate_data_tiers_include_data",
        "Elasticsearch isn't allowed to allocate some shards from these indices to any nodes in the desired data tiers because the "
            + "indices are configured with allocation filter rules that are incompatible with the nodes in this tier. ",
        "Remove ["
            + INDEX_ROUTING_INCLUDE_GROUP_PREFIX
            + ".data] from the index settings or try migrating to data tiers by first stopping ILM [POST /_ilm/stop] and then using "
            + "the data tier migration action [POST /_ilm/migrate_to_data_tiers]. Finally, restart ILM [POST /_ilm/start].",
        MIGRATE_TO_TIERS_ACTION_GUIDE
    );
    public static final Map<String, Diagnosis.Definition> ACTION_MIGRATE_TIERS_AWAY_FROM_INCLUDE_DATA_LOOKUP = DataTier.ALL_DATA_TIERS
        .stream()
        .collect(
            Collectors.toUnmodifiableMap(
                tier -> tier,
                tier -> new Diagnosis.Definition(
                    NAME,
                    "migrate_data_tiers_include_data:tier:" + tier,
                    "Elasticsearch isn't allowed to allocate some shards from these indices to any nodes in the ["
                        + tier
                        + "] data tier because the indices are configured with allocation filter rules that are incompatible with the "
                        + "nodes in this tier.",
                    "Remove ["
                        + INDEX_ROUTING_INCLUDE_GROUP_PREFIX
                        + ".data] from the index settings or try migrating to data tiers by first stopping ILM [POST /_ilm/stop] and then "
                        + "using the data tier migration action [POST /_ilm/migrate_to_data_tiers]. Finally, restart ILM "
                        + "[POST /_ilm/start].",