Objects mounted in shuttle areas drop again & relocates some shuttle objects (#94611)

## About The Pull Request
- Fixes #94119

> This will require a different solution which someone smarter than me
has to figure out in the foreseeable future

Today me is now smarter than yesterday me. We basically just unmount
when the object is about to shuttle moved and remount after it has been
shuttle moved

This also map edits some objects that could not be mounted in shuttles
previously

## Changelog
🆑
fix: objects mounted in shuttle areas deconstruct when their support
structure is destroyed
fix: fixes runtime in arrivals shuttle when its request console is
destroyed
map: moved around some objects in shuttles so they can be mounted on its
walls again
/🆑

code/game/objects/structures/signs/_signs.dm

@@ -207,7 +207,7 @@
 	playsound(target_turf, 'sound/items/deconstruct.ogg', 50, TRUE)
 	placed_sign.update_integrity(get_integrity())
 	placed_sign.setDir(dir)
-	placed_sign.AddComponent(/datum/component/atom_mounted, target_turf)
+	placed_sign.find_and_mount_on_atom()
 	qdel(src)
 	return ITEM_INTERACT_SUCCESS