Fix related data access to the full table name

These places accidentally used only "content_access" instead of full
linking table name. Nette's magic worked this out, but this could
cause issues for installations which could create similar linking
table. Nette wouldn't be able to resolve this afterwards.

src/Api/v1/UsersSubscriptionsHandler.php

@@ -75,7 +75,7 @@ public function handle(array $params): ResponseInterface
     private function formatSubscription($subscription, $subscriptionType)
     {
         $access = [];
-        foreach ($subscriptionType->related('content_access')->order('content_access.sorting') as $contentAccess) {
+        foreach ($subscriptionType->related('subscription_type_content_access')->order('content_access.sorting') as $contentAccess) {
             $access[] = $contentAccess->content_access->name;
         }