Webhooks - Occupancy event added

🚀 Feature Release

Occupancy is now available publicly to all webhook users.

Occupancy can be enabled in webhook by adding occupancy-sample-feed when create/modify a webhook in the dashboard or the API

Below is an example payload of the occupancy sample feed.
Note that null values will not be encoded into the payload:

{
  "id": "d7254d54-0d83-4b86-a927-895231426a67",
  "type": "airthings-webhook-cloudevent-occupancy-sample-feed",
  "source": "https://dashboard.airthings.com/integrations/webhooks/9a7c4f92-340a-4414-8175-2d09966931cc?version=v2",
  "dataContentType": "application/json",
  "labels": {},
  "data": [
    {
      "serialNumber": "2930000000",
      "measurementSystem": "METRIC",
      "recorded": "2023-06-28T12:25",
      "occupantsUpper": 0, // can be null
      "occupants": 0,
      "occupantsLower": 0, // can be null
      "sensorUnits": {
        "occupants": "occ"
      }
    }
  ],
  "time": "2023-06-28T12:30:08.463483",
  "specVersion": "0.2"
}