More trap doors (mostly interior)

DungeonGen refinements
--More Big Key door considerations
--Backtracks earlier when hook candidates comes up empty
Minor work on key shuffling - lots of bad rules still
Playthrough gen doesn't flood swamp keys now

Main.py

@@ -381,7 +381,7 @@ def create_playthrough(world):
         if not world.keysanity:
             state.sweep_for_events(key_only=True)
 
-        sphere = list(filter(state.can_reach, required_locations))
+        sphere = list(filter(lambda loc: state.can_reach(loc) and state.not_flooding_a_key(world, loc), required_locations))
 
         for location in sphere:
             required_locations.remove(location)