### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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/test/java/org/elasticsearch/xpack/security/authc/ApiKeyServiceTests.java
assertEquals(new BytesArray("{}"), apiKeyDoc.roleDescriptorsBytes);
    }
    public void testGetApiKeyMetadata() throws IOException {
        final Map<String, Object> metadata;
        final Map<String, Object> apiKeyMetadata = ApiKeyTests.randomMetadata();
        if (apiKeyMetadata == null) {
            metadata = Map.of(API_KEY_ID_KEY, randomAlphaOfLength(20));
        } else {
            final BytesReference metadataBytes = XContentTestUtils.convertToXContent(apiKeyMetadata, XContentType.JSON);
            metadata = Map.of(API_KEY_ID_KEY, randomAlphaOfLength(20), API_KEY_METADATA_KEY, metadataBytes);
        }
        final Authentication apiKeyAuthentication = Authentication.newApiKeyAuthentication(
            AuthenticationResult.success(new User(ESTestCase.randomAlphaOfLengthBetween(3, 8)), metadata),
            randomAlphaOfLengthBetween(3, 8)
        );
        final Map<String, Object> restoredApiKeyMetadata = ApiKeyService.getApiKeyMetadata(apiKeyAuthentication);
        if (apiKeyMetadata == null) {
            assertThat(restoredApiKeyMetadata, anEmptyMap());
        } else {
            assertThat(restoredApiKeyMetadata, equalTo(apiKeyMetadata));
        }
        final Authentication authentication = AuthenticationTests.randomAuthentication(
            AuthenticationTests.randomUser(),
            AuthenticationTests.randomRealmRef(randomBoolean()),
            false
        );
        final IllegalArgumentException e = expectThrows(
            IllegalArgumentException.class,
            () -> ApiKeyService.getApiKeyMetadata(authentication)
        );