Added support for an Hall Effect sensor to retrieve the current and calulate Wh

Update Marlin_main.cpp

Update ultralcd.h

Update ultralcd.cpp

Update ConfigurationStore.cpp

Update pins.h

Add the menu for the LCD Contrast only if is a declared pin

defined LCD_CONTRAST -1 for each MB as a default

Enable LCD contrast function only if there is a pin decleared

Enable LCD contrast gcode only if there is a pin decleared