Allow Security Assistants to roll antag roles.

[Flaborized]

Sec assistants are meant to be both for newbies learning how sec operates and also for people who wanna play sec but in a more relaxed role than regular sec officers.

In my eyes it's less about the actual power levels than it is about how sec assistants are meant to be trustworthy so they can do their role. The detective is a Special Case and people treat the det a little different because they can be antag, which I think is fun for that job but would change the vibe of secass a little too much. If you can't trust them anymore they kinda fail to be the sec officer-lite that they're meant to be. Plus it makes the det a little bit less Special