### 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
if (timeoutTask != null) {
                            timeoutTask.cancel();
                        }
                        listener.onFailure(e);
                    }
                }
                private void searchReady() {
                    if (isDone.compareAndSet(false, true)) {
                        if (timeoutTask != null) {
                            timeoutTask.cancel();
                        }
                        runAsync(executor, executable, listener);
                    }
                }
            });
        } catch (Exception e) {
            listener.onFailure(e);
        }
    }
    private IndexShard getShard(ShardSearchRequest request) {
        final ShardSearchContextId contextId = request.readerId();
        if (contextId != null) {
            if (sessionId.equals(contextId.getSessionId())) {
                final ReaderContext readerContext = activeReaders.get(contextId.getId());
                if (readerContext != null) {
                    return readerContext.indexShard();
                }
            }
        }
        return indicesService.indexServiceSafe(request.shardId().getIndex()).getShard(request.shardId().id());