Qbox jobs: add and edit jobs

A job in Qbox is a role a player can hold, like police or mechanic. Every job has grades, which are the ranks inside that job, like Recruit then Officer then Chief. Jobs are not in a database. They live in one Lua file, qbx_core/shared/jobs.lua, as a plain Lua table. qbx_core is the core framework resource (the program that runs the whole roleplay framework). You edit the file, restart that one resource, and the new job exists.