### Description

The [Get API key information API](https://www.elastic.co/guide/en/elasticsearch/reference/master/security-api-get-api-key.html) can currently filter the returned keys by:
 * key id/name
 * keys owned by the calling user
 * keys owned by other users, by `realm_name` and `username`

Irrespective of the filtering used, both invalidated and expired (but not yet deleted) keys will be included in the response.
In the response, keys have the `invalidated` boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.

I propose we introduce a way for the API to support retrieving:
* only valid API keys (not return invalidated keys) - using a boolean request parameter
* keys not expired before a certain timestamp - using a timestamp parameter that defaults to "now" - also note that keys' experiation date is always checked against the local node's clock
x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/authc/ApiKeyService.java
false,
                
                this::convertSearchHitToApiKeyInfo,
                ActionListener.wrap(apiKeys -> {
                    if (apiKeys.isEmpty()) {
                        logger.debug(
                            "No active api keys to invalidate for realms {}, username [{}], api key name [{}] and api key ids {}",
                            Arrays.toString(realmNames),
                            username,
                            apiKeyName,
                            Arrays.toString(apiKeyIds)
                        );
                        invalidateListener.onResponse(InvalidateApiKeyResponse.emptyResponse());
                    } else {
                        indexInvalidation(apiKeys.stream().map(ApiKey::getId).collect(Collectors.toSet()), invalidateListener);
                    }
                }, invalidateListener::onFailure)
            );
        }
    }
    private <T> void findApiKeys(
        final BoolQueryBuilder boolQuery,
        boolean filterOutInvalidatedKeys,
        boolean filterOutExpiredKeys,
        final Function<SearchHit, T> hitParser,
        final ActionListener<Collection<T>> listener
    ) {
        if (filterOutInvalidatedKeys) {
            boolQuery.filter(QueryBuilders.termQuery("api_key_invalidated", false));
        }