Now exposing a counter of received messages

[zubairov]

Could be useful to see which sensors are sending data and which are not (e.g. when outside of range)

[kpetremann]

FYI you can do a similar thing with existing metrics, like this:

name: sensor_no_fresh_data
expr: changes(zigbee_temperature[4h]) == 0
for: 15m
labels:
  severity: notification-daily
annotations:
  description: Sensor data did not change for 4 hours: {{ $labels.sensor }}
  sumary: No fresh data (> 4h) for {{ $labels.sensor }}

assuming the sensor is always sending different values.