### 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
this.indicesService = indicesService;
        this.scriptService = scriptService;
        this.responseCollectorService = responseCollectorService;
        this.bigArrays = bigArrays;
        this.fetchPhase = fetchPhase;
        this.multiBucketConsumerService = new MultiBucketConsumerService(
            clusterService,
            settings,
            circuitBreakerService.getBreaker(CircuitBreaker.REQUEST)
        );
        this.executorSelector = executorSelector;
        this.tracer = tracer;
        TimeValue keepAliveInterval = KEEPALIVE_INTERVAL_SETTING.get(settings);
        setKeepAlives(DEFAULT_KEEPALIVE_SETTING.get(settings), MAX_KEEPALIVE_SETTING.get(settings));
        clusterService.getClusterSettings()
            .addSettingsUpdateConsumer(
                DEFAULT_KEEPALIVE_SETTING,
                MAX_KEEPALIVE_SETTING,
                this::setKeepAlives,
                SearchService::validateKeepAlives
            );
        this.keepAliveReaper = threadPool.scheduleWithFixedDelay(new Reaper(), keepAliveInterval, Names.SAME);
        defaultSearchTimeout = DEFAULT_SEARCH_TIMEOUT_SETTING.get(settings);
        clusterService.getClusterSettings().addSettingsUpdateConsumer(DEFAULT_SEARCH_TIMEOUT_SETTING, this::setDefaultSearchTimeout);
        defaultAllowPartialSearchResults = DEFAULT_ALLOW_PARTIAL_SEARCH_RESULTS.get(settings);
        clusterService.getClusterSettings()
            .addSettingsUpdateConsumer(DEFAULT_ALLOW_PARTIAL_SEARCH_RESULTS, this::setDefaultAllowPartialSearchResults);
        maxOpenScrollContext = MAX_OPEN_SCROLL_CONTEXT.get(settings);
        clusterService.getClusterSettings().addSettingsUpdateConsumer(MAX_OPEN_SCROLL_CONTEXT, this::setMaxOpenScrollContext);
        lowLevelCancellation = LOW_LEVEL_CANCELLATION_SETTING.get(settings);