Flashlights, stunbatons, and lanterns power changes

- Flashlights use default regular 1000 charge cells now.
They drain 3 charge every ~2 seconds when on, with an estimated lifespan of 10 minutes.

- Stun batons will slowly drain power when they're turned on.
They drain 5 charge every ~2 seconds, with an estimated lifespan of 10 minutes (stun batons/prods require high capacity cells with 1500 charge.)

- Lanterns will require welding fuel.
They have a 25% change of draining 1 fuel reagent every ~2 seconds when turned on, and have 50 fuel total. They can be refuelled at welding fuel tanks.

Additional ideas to balance this properly would be nice, I'm not too good at this sort of balancing, especially when it comes to mining. Lanterns are seemingly useless as fuck with the mining rig's floodlights, but that is going to be changed in the upcoming weeks so don't worry about that.

This PR kind of makes fire helmets and hardhats pretty OP, but that's also kind of okay because nobody ever uses those enough anyway. They may be changed to require cells and such perhaps, but not in this PR.
This too, please not in update_icon, move to toggle/make special proc/whatever, just not update_icon