Feature: Double contactor support + NC support

[dalathegreat]

What

This PR implements GPIO contactor closing when running 2x batteries. It also adds support for using NC relays connected to the pins.

Why

User requested feature

How

USER_SETTINGS have been modified, contactor options branched out to its own section. 2 new options added, NC_CONTACTORS and CONTACTOR_CONTROL_DOUBLE_BATTERY

• Note#1. No precharge on secondary battery. It is allowed to join in once mVdiff is less than 3VDC
• Note#2 This functionality requires board with 2x more GPIOs to run. Only 3LB hardware supports this for now. If you want to run

[dalathegreat]

Tested OK on the Discord on a 3LB board :raised_hands: