### Description

In [siren federate](https://siren.io/federate/) we extend the `SearchService` to create `SearchContext` instances. In 8.8 this is not possible anymore because the `createContext` method takes the `ResultsType` enum which is package private.

https://github.com/elastic/elasticsearch/blob/b640c217cccab67dce7d954bc92b6b519c102b16/server/src/main/java/org/elasticsearch/search/SearchService.java#L992-L998

In order to be able to keep on calling that method from another package, the visibility of the enum `ResultsType` should be increased to `protected`.
server/src/main/java/org/elasticsearch/search/SearchService.java
private final FetchPhase fetchPhase;
    private volatile long defaultKeepAlive;
    private volatile long maxKeepAlive;
    private volatile TimeValue defaultSearchTimeout;
    private volatile boolean defaultAllowPartialSearchResults;
    private volatile boolean lowLevelCancellation;
    private volatile int maxOpenScrollContext;
    private volatile boolean enableRewriteAggsToFilterByFilter;
    private final Cancellable keepAliveReaper;
    private final AtomicLong idGenerator = new AtomicLong();
    private final Map<Long, ReaderContext> activeReaders = ConcurrentCollections.newConcurrentMapWithAggressiveConcurrency();
    private final MultiBucketConsumerService multiBucketConsumerService;
    private final AtomicInteger openScrollContexts = new AtomicInteger();
    private final String sessionId = UUIDs.randomBase64UUID();
    private final Tracer tracer;
    public SearchService(
        ClusterService clusterService,
        IndicesService indicesService,
        ThreadPool threadPool,
        ScriptService scriptService,
        BigArrays bigArrays,
        FetchPhase fetchPhase,
        ResponseCollectorService responseCollectorService,
        CircuitBreakerService circuitBreakerService,
        ExecutorSelector executorSelector,
        Tracer tracer
    ) {
        Settings settings = clusterService.getSettings();
        this.threadPool = threadPool;
        this.clusterService = clusterService;