Clean up NotesDatabase

    private static final String TAG = NotesDatabase.class.getSimpleName();

    private static final String[] columnsWithoutContent = {key_id, key_remote_id, key_status, key_title, key_modified, key_favorite, key_category, key_etag, key_excerpt};

    private static final String[] columns = {key_id, key_remote_id, key_status, key_title, key_modified, key_favorite, key_category, key_etag, key_excerpt, key_content};

    private static final String default_order = key_favorite + " DESC, " + key_modified + " DESC";

    private static NotesDatabase instance;

     * @param search    The search pattern

     * @return The category list containing all of the categories matched

     */

    // TODO merge with getCategories(long accountId)

    @NonNull

    @WorkerThread

    public List<NavigationAdapter.NavigationItem> searchCategories(long accountId, String search) {