Get notification graph statistics

curl --request GET \
  --url https://api.novu.co/v1/notifications/graph/stats \
  --header 'Authorization: <authorization>'

{
  "data": [
    {
      "_id": "string",
      "channels": [
        "in_app"
      ],
      "count": "number",
      "templates": [
        "string"
      ]
    }
  ]
}