on_nan_value for sensor

**Describe the problem you have/What new integration you would like**

on_nan_value:
- switch.turn_off: relay_D2

**Please describe your use case for this integration and alternatives you've tried:**

my current construction

on_raw_value:
then:
- lambda: !lambda |-
if (isnan(id(temp).raw_state)) id(relay_D2).turn_off();

**Additional context**

looks better

The request names the sensor callbacks on_nan_value and on_raw_value plus a lambda action; start by tracing how sensor automations and NaN states are currently handled. Done means a sensor configuration can invoke the requested switch.turn_off action when its value is NaN, with coverage for the relevant behavior.

Written by the indexing model from the issue text.