Support unique_id for serial sensor

A common usage pattern for the serial integration is to define a serial sensor which contains a json blob or csv string value, and then define a template which extracts values as derived sensors.

However, it’s not possible to hide the source serial sensor entity because the sensor yaml configuration does not support setting unique_id.

This forum topic is a good example of the problem:

How do I disable ‘source sensors’ and keep the templated ones? - Configuration / Frontend - Home Assistant Community (home-assistant.io)