### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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
public void testApiKeyAuthCacheWillTraceLogOnEvictionDueToCacheSize() throws IllegalAccessException {
        final int cacheSize = randomIntBetween(2, 8);
        ApiKeyService service = createApiKeyService(
            Settings.builder().put("xpack.security.authc.api_key.cache.max_keys", cacheSize).build()
        );
        final Cache<String, ListenableFuture<CachedApiKeyHashResult>> apiKeyAuthCache = service.getApiKeyAuthCache();
        
        final String idPrefix = randomAlphaOfLength(20);
        final AtomicInteger count = new AtomicInteger(0);
        IntStream.range(0, cacheSize).forEach(i -> apiKeyAuthCache.put(idPrefix + count.incrementAndGet(), new ListenableFuture<>()));
        final Logger logger = LogManager.getLogger(ApiKeyService.class);
        Loggers.setLevel(logger, Level.TRACE);
        final MockLogAppender appender = new MockLogAppender();
        Loggers.addAppender(logger, appender);
        appender.start();
        try {
            appender.addExpectation(
                new MockLogAppender.PatternSeenEventExpectation(
                    "evict",
                    ApiKeyService.class.getName(),
                    Level.TRACE,
                    "API key with ID \\[" + idPrefix + "[0-9]+\\] was evicted from the authentication cache.*"
                )
            );
            appender.addExpectation(
                new MockLogAppender.UnseenEventExpectation(
                    "no-thrashing",
                    ApiKeyService.class.getName(),
                    Level.WARN,
                    "Possible thrashing for API key authentication cache,*"