List webhook endpoints

{  "items": [    {      "id": "string",      "user_id": "string",      "organization_id": "string",      "url": "string",      "description": "string",      "event_types": [        "*"      ],      "all_accounts": true,      "connection_ids": [        "string"      ],      "secret": "string",      "enabled": true,      "created_at": "2019-08-24T14:15:22Z",      "updated_at": "2019-08-24T14:15:22Z",      "deleted_at": "2019-08-24T14:15:22Z"    }  ]}

{  "error": "string"}