Fabric per player spawns

Forked from Lambdacraft because he went afk. >This mod is intended to distribute mobs evenly between all players on a fabric modloaded server. I rewired the mixins to work with 1.16.5, and then just rewrote that part of the mod as I see fit. How it works:  - modifies spawn logic to count chunks (and mobs in them) in a (square) radius around the player and account for chunks shared between the players - radius to account is based on (server) render distance (like mob caps in vanilla) - in the end each player has their own mob cap which applies to chunks around that player. (the most full one is applied in case of overlap) - hold glistering melon in creative/spectator to see debug info \[This means if two players are relatively close to each other\*\*, they can either have 70\* mobs in the area between them, or 70\* mobs each if no mobs are between them. Though, usually, it will be 70\*⋅1.5\*\*=105 mobs, as intended by vanilla.\]\ \* default monster mobcap, can be changed\ \*\* ~1 server render distance; n_chunks_loaded_by_these_playres/(SRD⋅2+1)²   Works with [Proper Mobcap Modifier](https://modrinth.com/mod/proper-mobcap-modifier-(fabric)) (by me)