Bunch of crew AI bugfixes/improvements:

- replacing empty oxygen tanks
- fixed characters only fixing leaks in the outer hull
- prioritizing large leaks over small ones
- fixed characters doing nothing after fixing all the leaks (and sinking to the bottom if they happen to be outside)
- more accurate welder aiming
- AIObjectiveGetItem makes the characters go to the cabinet/container an item is inside, not to the actual item (which may not be actually positioned at the container)

Subsurface/Source/Characters/AI/Objectives/AIObjectiveIdle.cs

@@ -40,8 +40,11 @@ namespace Barotrauma
 
                 if (currentTarget != null)
                 {
-                    var path = pathSteering.PathFinder.FindPath(character.SimPosition, currentTarget.SimPosition);
-                    if (path.Cost > 200.0f) return;
+                    Vector2 pos = character.SimPosition;
+                    if (character != null && character.Submarine == null) pos -= Submarine.Loaded.SimPosition;
+                    
+                    var path = pathSteering.PathFinder.FindPath(pos, currentTarget.SimPosition);
+                    if (path.Cost > 200.0f && character.AnimController.CurrentHull!=null) return;
 
                     pathSteering.SetPath(path);
                 }