Fix placement of RatingSummaryService

bazaarvoice_rating_summary module was implemented in https://www.drupal.org/project/bazaarvoice/issues/3197369

But looks like RatingSummaryService.php and RatingSummaryServiceInterface.php files for bazaarvoice.rating_summary service were placed into wrong folder, cause right now I got error Error : Class "Drupal\bazaarvoice_rating_summary\Service\RatingSummaryService"

these files are placed in src/Service folder of bazaarvoice module, while they should be placed in modules/bazaarvoice_rating_summary/src/Service