Crate slowdown

[Chasu]

I would enjoy this change, however I belive there should be 3 teirs of slowdowns.
Empty to 10: slight slowdown
11 to 50: Slowdown equal to the middle of both
51 to max or atleast 1 corpse: Harsh slowdown like having 1 body in it is now.

I also belive if the sprite has wheels the slowdown should either be heavily negated or removed like trash carts and engi carts

I could imagine a system like this, but instead of the amount of items, their weight classes/values are added together. i.e. lots of tiny objects are on the same slowdown tier as one bulky object