Adds the Odyssey gamemode. (#18972)

https://forums.aurorastation.org/topic/20198-mission-briefing-auroras-gamemode-revolution

To-do:

- [x] Finish storyteller verbs.
- [x] Storyteller landmarks.
- [x] Proper storyteller spawning. Right now the gamemode system is
happy with just picking one storyteller and no actors.
- [x] Antagonist whitelists code.
- [x] Adding the Storyteller whitelist.
- [x] Mission map loading code.
- [x] Map in a bunch of missions.
- [ ] Storyteller adminhelps.

---------

Co-authored-by: Matt Atlas <liermattia@gmail.com>
Co-authored-by: DreamySkrell <>

code/modules/effects/map_effects/map_effects.dm

@@ -60,7 +60,7 @@
 
 	for(var/thing in GLOB.player_list)
 		var/mob/M = thing // Avoiding typechecks for more speed, player_list will only contain mobs anyways.
-		if(ignore_ghosts && isobserver(M))
+		if(ignore_ghosts && isghost(M))
 			continue
 		if(ignore_afk && M.client && M.client.is_afk(5 MINUTES))
 			continue