### 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
ShardSearchRequest request,
        IndexService indexService,
        IndexShard shard,
        Engine.SearcherSupplier reader,
        long keepAliveInMillis
    ) {
        ReaderContext readerContext = null;
        Releasable decreaseScrollContexts = null;
        try {
            if (request.scroll() != null) {
                decreaseScrollContexts = openScrollContexts::decrementAndGet;
                if (openScrollContexts.incrementAndGet() > maxOpenScrollContext) {
                    throw new ElasticsearchException(
                        "Trying to create too many scroll contexts. Must be less than or equal to: ["
                            + maxOpenScrollContext
                            + "]. "
                            + "This limit can be set by changing the ["
                            + MAX_OPEN_SCROLL_CONTEXT.getKey()
                            + "] setting."
                    );
                }
            }
            final ShardSearchContextId id = new ShardSearchContextId(sessionId, idGenerator.incrementAndGet());
            if (request.scroll() != null) {
                readerContext = new LegacyReaderContext(id, indexService, shard, reader, request, keepAliveInMillis);
                if (request.scroll() != null) {
                    readerContext.addOnClose(decreaseScrollContexts);
                    decreaseScrollContexts = null;
                }
            } else {