Implement more important mechanics for PvP

[Kumpelinus]

There are a few more things that are still to do:

• Drinkable Potions + Food (including Golden Apples)
• Projectiles like eggs, snowballs, splash potions
• Fishing rod
• Despawning timer for things like Arrows
• Arrow pickup

[Kumpelinus]

Assigning this to myself since I already started working on it. I only created this Issue so others don't work on the same stuff as I do.

[Kumpelinus]

Despawning timer might already be implemented by #772.