Xenomorphs are pretty much badly done and don't really fit at all. This pr fully removes the human type ones, alongside with the infection, eggs and facehuggers.
Gamemodes that haphazardly crash two or more other gamemodes together are now explained in their voting option, so we can stop having to explain it to OoC literally every round
-allow voting for most mixed gamemodes, with exception of bughunt and infection
-adds crossfire(merc and heister), also adds a raider frequency to don't mix them with mercs
-adds siege(rev and merc)
-adds visitors(ninja and wizard)
