Refactor job assignment code to improve job distribution variety

[Sovexe]

About the PR

• Changes job assignment to be player preference driven rather than attempting to fill out each role in a random order
• refactors a lot of duplicated garbage into a single massive trash pile
• moves some globals/global logic to the job_controls datum, mostly just to reduce the number of pointlessly global procs

Why's this needed?

• The current job assignment system attempts to randomly fill out a role entirely before going onto the next. This means that we'd often get entirely full roles while others were empty, despite both roles being equally desired by players

Changelog

(u)Sovexe
(*)Refactored job assignment code. Jobs variety should improve overall. Unless this change breaks everything.