Invert Modbus binary sensor

[sean797]

Many other integrations have ways to invert values, MQTT has payload_on & payload_off for example. But there isnt a way to invert vaules with the modbus integration.

Examples of users facing problems:

• Invert / reverse the output of modbus binary door sensor
• https://www.reddit.com/r/homeassistant/comments/1jcgs94/inverted_modbus_window_sensor/