Changes to Listar endpoints de webhook

the response property next_cursor became nullable for the status 200

added the new product.created enum value to the data/items/enabled_events/items response property for the response status 200

added the new product.updated enum value to the data/items/enabled_events/items response property for the response status 200

added the new enum value product.created to the query request parameter event_type

added the new enum value product.updated to the query request parameter event_type

added the non-success response with the status 503

added the optional property error/details/items/metadata to the response with the 400 status

added the optional property error/details/items/metadata to the response with the 401 status

added the optional property error/details/items/metadata to the response with the 403 status

added the optional property error/details/items/metadata to the response with the 429 status

added the optional property error/details/items/metadata to the response with the 500 status

response property next_cursor list-of-types was narrowed by removing types null from media type application/json of response 200