### 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boolean property, as well as the `expiration` property that contains the UNIX timestamp past of which the key is no longer valid for authentication.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
when(client.prepareBulk()).thenReturn(new BulkRequestBuilder(client, BulkAction.INSTANCE));
        final var updateRequestBuilder = Mockito.spy(new UpdateRequestBuilder(client, UpdateAction.INSTANCE));
        when(client.prepareUpdate(eq(SECURITY_MAIN_ALIAS), eq(apiKeyId))).thenReturn(updateRequestBuilder);
        
        doAnswer(invocation -> {
            final var listener = (ActionListener<BulkResponse>) invocation.getArguments()[1];
            listener.onResponse(
                new BulkResponse(
                    new BulkItemResponse[] {
                        BulkItemResponse.success(
                            docId,
                            DocWriteRequest.OpType.UPDATE,
                            new UpdateResponse(
                                mock(ShardId.class),
                                apiKeyId,
                                randomLong(),
                                randomLong(),
                                randomLong(),
                                DocWriteResponse.Result.UPDATED
                            )
                        ) },
                    randomLongBetween(1, 100)
                )
            );
            return null;
        }).when(client).bulk(any(BulkRequest.class), anyActionListener());
        doAnswer(invocation -> {
            final var listener = (ActionListener<ClearSecurityCacheResponse>) invocation.getArguments()[2];
            listener.onResponse(mock(ClearSecurityCacheResponse.class));