Attempts to increase the stability of grimac on a 1.18 server. Note that there are still major issues on 1.8, and if you are using pre-1.17 versions, you'll run into significant issues.

Bugs fixed:
- Respawn packet throwing an out of bounds exception
- Exceptions from bukkitPlayer being null
- World height NBT code being spaghetti
- Useless mount packets causing vehicle to be null