Build listings response

[MAILPOET-2657]

lib/Subscribers/SubscriberListingRepository.php

@@ -3,6 +3,7 @@
 namespace MailPoet\Subscribers;
 
 use MailPoet\Entities\SubscriberEntity;
+use MailPoet\Listing\ListingDefinition;
 use MailPoet\Listing\ListingRepository;
 use MailPoetVendor\Doctrine\ORM\QueryBuilder;
 
@@ -59,4 +60,12 @@ class SubscriberListingRepository extends ListingRepository {
     $queryBuilder->addOrderBy("s.$sortBy", $sortOrder);
   }
 
+  public function getGroups(ListingDefinition $definition): array {
+    return [];// TODO
+  }
+
+  public function getFilters(ListingDefinition $definition): array {
+    return [];//TODO
+  }
+
 }