### 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
clusterService.getClusterSettings().addSettingsUpdateConsumer(LOW_LEVEL_CANCELLATION_SETTING, this::setLowLevelCancellation);
        enableRewriteAggsToFilterByFilter = ENABLE_REWRITE_AGGS_TO_FILTER_BY_FILTER.get(settings);
        clusterService.getClusterSettings()
            .addSettingsUpdateConsumer(ENABLE_REWRITE_AGGS_TO_FILTER_BY_FILTER, this::setEnableRewriteAggsToFilterByFilter);
    }
    private static void validateKeepAlives(TimeValue defaultKeepAlive, TimeValue maxKeepAlive) {
        if (defaultKeepAlive.millis() > maxKeepAlive.millis()) {
            throw new IllegalArgumentException(
                "Default keep alive setting for request ["
                    + DEFAULT_KEEPALIVE_SETTING.getKey()
                    + "]"
                    + " should be smaller than max keep alive ["
                    + MAX_KEEPALIVE_SETTING.getKey()
                    + "], "
                    + "was ("
                    + defaultKeepAlive
                    + " > "
                    + maxKeepAlive
                    + ")"
            );
        }
    }
    private void setKeepAlives(TimeValue defaultKeepAlive, TimeValue maxKeepAlive) {
        validateKeepAlives(defaultKeepAlive, maxKeepAlive);
        this.defaultKeepAlive = defaultKeepAlive.millis();
        this.maxKeepAlive = maxKeepAlive.millis();
    }
    private void setDefaultSearchTimeout(TimeValue defaultSearchTimeout) {
        this.defaultSearchTimeout = defaultSearchTimeout;
    }