Projectiles

[peternga]

Adds projectiles to the game and allow players to shoot them. I think it might make more sense to have these projectiles attached to weapons and give players the ability to switch out weapons, but this works!

• Projectiles move slow enough for players to hurt themselves.
• Projectiles disappear upon any collision. This means projectiles will cancel themselves out
• Projectiles don't time out and don't wrap. This may cause memory leaks if players shoot into the edge of the map
• Projectiles only support left and right trajectories. No other directions
• Players don't have a way of indicating direction. As such, projectiles only fire in one direction for now.

https://recordit.co/tKZz1GUOPM

[peternga]

Merging so we can have it available during gamedev meeting. Will address PR comments afterwards