Auxiliary Systems Functionality

[colbycheese55]

passed test - ✅
failed test - ❌
not yet tested - ?

State, Date	Topic	Comments
✅	Turn signals are controlled by turn signal buttons
✅	Turn signals flash when hazards are enabled, regardless of turn signal switch state
✅	DRLs are on when charging mode is disabled, and vice versa
?	Brake lights work, both when the brake pedal is pressed and when regen braking
✅	Aux battery reading is correct