List the caller's notifications and unread count

{  "items": [    {      "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",      "type": "publish",      "title": "string",      "ref": "string",      "read": true,      "createdAt": "2019-08-24T14:15:22Z"    }  ],  "unreadCount": 0}

{  "defined": true,  "code": "UNAUTHORIZED",  "status": 401,  "message": "Authentication required or credentials invalid.",  "data": null}

{  "defined": true,  "code": "VALIDATION",  "status": 422,  "message": "The input failed domain validation.",  "data": {    "issues": [      {        "path": "string",        "message": "string"      }    ]  }}

{  "defined": true,  "code": "RATE_LIMITED",  "status": 429,  "message": "Rate limit exceeded; retry later.",  "data": {    "retryAfterSeconds": -9007199254740991  }}