Hide NightVision while Helmet is slung

[Zarrck]

Or maybe put it into the inventory or something.

Reason: It looks pretty bad if you have goggles on your head without a helmet. Manually having to remove them every time is counterintuitive to the ease of use of the ACE function.

[DerZade]

I'm not sure if I would like this change 🤔, because not having NVGs is a big deal. How would you communicate to the player, that the NVGs are "with" his slung helmet?

This should at least be configurable, because I can think of use cases, where I need my NVGs, although I want my helmet slung.

[Zarrck]

We already discussed this in the past and then decided against it (Issue #16 ).
I decided to revisit the discussion beacuse of popular demand in recent missions.

If we end up implementing this it should certainly be an optional feature.

For the issue of communication to the player: I would add a hint when slinging the helmet if a NVG was removed