ScriptableObjects and UnityEvents

[ronnnnnnnnn]

• Created ScriptableObjects for player sprites
• Created ScriptableObjects for projectile data and an abstract class for projectile behaviour
• All this should, in theory, allow for more modular code and make it easier to design new projectiles
• Enemy tank turret now rotates during aiming, but the movement is still kind of janky
• Since it's basically the same thing, both player and enemy health are now the same script
• Rewrote some game logic using UnityEvents, which I think we should start using instead of GetComponent as it's a neater way to implement interactions between scripts