[Feature] Prevent player RNG cracking / manipulation

[unilock]

Paper includes a patch that makes all entities use a shared RandomSource, making it much more difficult for a player to "crack" their own RNG, e.g. for the purpose of manipulating the enchantments given by an Enchanting Table. (see: clientcommands' SeedCracker)

This is Paper's patch: https://github.com/PaperMC/Paper/blob/master/patches/server/0074-Use-a-Shared-Random-for-Entities.patch

It seems simple enough. I'd even make a PR implementing it myself, if I were at a computer :p