Add wall effect particles to visualize borders

[Jaxkr]

Why? Sometimes players are confused by the world slicing mechanics and don't understand what is happening when they cannot cross server boundaries due to them being on cooldown.

What? Whenever a player bounces off a server boundary because they're on server transfer cooldown, display a wall of particles momentarily that visualizes the server border.

How? Find the dmz line and wall direction (which will be perpendicular to the shove direction) and then use the players current position to know which y value to draw a 4x4 wall of particles at.

[Jaxkr]

[Saiv46]

Why not use world border instead? You only need to update it's center and size.