Outdoor temperature compensation

What's new:

• Added the outdoor_sensor to select an outdoor temperature sensor and ke gain settings to enable outdoor temperature compensation.
  The thermostat can then automatically compensate building losses based on the difference between target temperature and
  outdoor temperature. An external component E is added to the PID output:
  E = Ke * (target_temp - outdoor_temp)
output = P + I + D + E
  The Ke gain depends on the insulation of the building, on recent buildings with good insulation, a
  gain of 0.6 is recommended. This compensation will act like the integral of the PID, but with
  faster response time, so the integral will be more stable.
• Automatically adjust heater on and off duration based on min_cycle_duration and min_off_cycle_duration parameters for better modulation accuracy.
• When temperature is changed, the preset mode is automatically activated if a preset corresponds to the set temperature, or deactivated when no preset matches.

Bug fixes:

• Preset temperature is not restored on restart
• Heating duration exceeds min_cycle_duration #57
• On/Off adjustment duration causes heater not switching on #56
• Preset remains unchanged after changing target temperature #54
• Division by zero error during PWM calc when PID output is 0 or 100% #53
• Float numbers with too big accuracy #52

Full Changelog: 2021.12.4...2021.12.5