This PR splits the ERT file up into a bunch of files, to edit them later much easier.
1 Doctor (Lead), intended to do advanced medical stuff to heal people.
2 Paramedics, intended to bring injured to the doctor. (Can likely also do advanced medical stuff, but the doctor should be the primary one to do so)
1 Bodyguard, intended to stay with and defend in the IAC team. (Also trained in medical procedures, but not super advanced.)
all antags that previously had massive equip chains now use the outfit datum system
commandos + deathsquad (aka Syndicate Commandos and NT Asset Protection) have been moved out of nested alert menu hell to the new ERT system as admin-spawned ERTs, they do not appear normally
all outfit datums will now take into account backpack preferences
made the ERT job announcement / details more obvious
