Hotfixes 2024-03-21

Fix so Croa Corpses don't show that they can be stored in their Properties tab even though they can't.
Fix crash when a Student Arrival event triggers, but there is no place to add the student.
Fix position of the ladder placemarker.
Fix for broken Mages corpses when they died in unpathable locations, like in a wall while being carried by the Founder.
Fix for Messy Meddlers sometimes not being able to create messes.
Rifts when Poltergeists are arriving no longer block pathing.
Fix for Croa sometimes not being able to sleep at their nest during the day.
Make Small Carcass be carried in the proper position visually.