### 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 void freeAllContextsForShard(ShardId shardId) {
        assert shardId != null;
        for (ReaderContext ctx : activeReaders.values()) {
            if (shardId.equals(ctx.indexShard().shardId())) {
                freeReaderContext(ctx.id());
            }
        }
    }
    public boolean freeReaderContext(ShardSearchContextId contextId) {
        if (sessionId.equals(contextId.getSessionId())) {
            try (ReaderContext context = removeReaderContext(contextId.getId())) {
                return context != null;
            }
        }
        return false;
    }
    public void freeAllScrollContexts() {
        for (ReaderContext readerContext : activeReaders.values()) {
            if (readerContext.scrollContext() != null) {
                freeReaderContext(readerContext.id());
            }
        }
    }
    private long getKeepAlive(ShardSearchRequest request) {
        if (request.scroll() != null) {
            return getScrollKeepAlive(request.scroll());
        } else if (request.keepAlive() != null) {
            checkKeepAliveLimit(request.keepAlive().millis());
            return request.keepAlive().getMillis();