🐛 Fixed 500 error for content with no collection

no issue

- Fixes a case where a post that doesn't belong to a collection throws a 500 Resource Not Found Error
- This should be a 404 Resource Not Found error
- 500 suggests something went very wrong and is our fault,
-  but this is a user error where the collections or posts are misconfigured, and some content doesn't have a home

core/server/services/url/UrlService.js

@@ -137,7 +137,7 @@ class UrlService {
         const object = this.urls.getByResourceId(resourceId);
 
         if (!object) {
-            throw new common.errors.InternalServerError({
+            throw new common.errors.NotFoundError({
                 message: 'Resource not found.',
                 code: 'URLSERVICE_RESOURCE_NOT_FOUND'
             });