Bug fixes and improvements

Attempted fix for:

• #88 - Thanks to RamonQu for providing POST info!
• #133 - Attempted fix, unverified

Enhancements:

• #139 - Added switch for "plug auto unlock", untested
• #156 - Changed icon for door locks
• Added switch for window heating during climatisation (Enyaq) - Untested
• Added support for using heater source in climatisation service (aux heater for PHEV)
• Added switch for "Allow use of auxiliary heater for next departure" - Untested