Add craftable Smoke Flares!

[Peter34]

I just played a bit on my 8.6-started Navezgane solo player map, not having realized that 9.1 is apparently out, but I did notice something not documented in the 9.0 patch notes, which was a large column of orange smoke. I concluded that it was probably an Air Supply Drop that had been enhanced with some kind of coloured flare smoke, so I ran to it, and in fact it was. That's a cool improvement! But why not also re-use that programming to allow the player characters, in the game, to drop "smoke signal" bombs to send up columns of coloured smoke, in a small variety of colours. Just red, green, blue and yellow, perhaps? I can see various strategic uses for that, and there might be tactical ones as well for those who do PVP. I found the crate at around 1100 hours, so it'd have been dropped at least 23 hours earlier and more likely 47 hours earlier as I think I'm on the 2nd day of my 3-day drop schedule. So the smoke flare had been functioning for quite a long while. Obviously, player-droppable smoke flares should not work for a very long time. Ideally only about half an hour in-game time, I think. But having them would be nice for coop play.