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.

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

code/modules/admin/buildmode/edit.dm

@@ -1,6 +1,7 @@
 /datum/build_mode/edit
 	name = "Edit"
 	icon_state = "buildmode3"
+	permission_requirement = R_ADMIN
 	var/var_to_edit = "name"
 	var/value_to_set = "derp"