ACS712 sensor component for esphome

This is based on https://github.com/RobTillaart/ACS712

Refer to that README to initialize ACS object correctly.

The code is working on esp and ACS712-30A.

Watts estimation is done with a 220V supposed voltage.

Have in mind that without voltage divider on the ADC pin a 30A model will measure up to 20A.

Example yaml fragment:

esphome:
  name: tanque-agua
  friendly_name: tanque-agua
  libraries:
    - https://github.com/RobTillaart/ACS712.git
  includes:
    - acs712_component.h
    
sensor:
  - platform: custom
    lambda: |-
      auto acs712_sensor = new ACS712Sensor();
      App.register_component(acs712_sensor);
      return {acs712_sensor->current_sensor, acs712_sensor->power_sensor};
    sensors:
    - name: "Amperes"
      unit_of_measurement: A
      accuracy_decimals: 2
    - name: "Watts"
      unit_of_measurement: W
      accuracy_decimals: 2