### 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
);
    public static final Setting<Integer> MAX_OPEN_SCROLL_CONTEXT = Setting.intSetting(
        "search.max_open_scroll_context",
        500,
        0,
        Property.Dynamic,
        Property.NodeScope
    );
    public static final Setting<Boolean> ENABLE_REWRITE_AGGS_TO_FILTER_BY_FILTER = Setting.boolSetting(
        "search.aggs.rewrite_to_filter_by_filter",
        true,
        Property.Dynamic,
        Property.NodeScope
    );
    public static final Setting<ByteSizeValue> MAX_ASYNC_SEARCH_RESPONSE_SIZE_SETTING = Setting.byteSizeSetting(
        "search.max_async_search_response_size",
        new ByteSizeValue(10, ByteSizeUnit.MB),
        Property.Dynamic,
        Property.NodeScope
    );
    public static final int DEFAULT_SIZE = 10;
    public static final int DEFAULT_FROM = 0;
    private final ThreadPool threadPool;
    private final ClusterService clusterService;
    private final IndicesService indicesService;
    private final ScriptService scriptService;
    private final ResponseCollectorService responseCollectorService;
    private final ExecutorSelector executorSelector;
    private final BigArrays bigArrays;
    private final DfsPhase dfsPhase = new DfsPhase();