### 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,
        SearchShardTask task,
        ResultsType resultsType,
        boolean includeAggregations
    ) throws IOException {
        checkCancelled(task);
        final DefaultSearchContext context = createSearchContext(readerContext, request, defaultSearchTimeout);
        resultsType.addResultsObject(context);
        try {
            if (request.scroll() != null) {
                context.scrollContext().scroll = request.scroll();
            }
            parseSource(context, request.source(), includeAggregations);
            
            if (context.from() == -1) {
                context.from(DEFAULT_FROM);
            }
            if (context.size() == -1) {
                context.size(DEFAULT_SIZE);
            }
            if (request.rankQueryBuilders().isEmpty() == false) {
                List<Query> rankQueries = new ArrayList<>();
                for (QueryBuilder queryBuilder : request.rankQueryBuilders()) {
                    rankQueries.add(queryBuilder.toQuery(context.getSearchExecutionContext()));
                }
                context.rankShardContext(request.source().rankBuilder().buildRankShardContext(rankQueries, context.from()));
            }
            context.setTask(task);
            context.preProcess();
        } catch (Exception e) {