(2a7829fab) Add ISpatialEntity as a common interface for everything that has a position in the game world. Would have used IMapEntity, but there's already MapEntity, which inherits Entity, so that would be confusing. Declare the inheritance only in the shared class (Character).

Barotrauma/BarotraumaShared/Source/Map/ISpatialEntity.cs

@@ -0,0 +1,12 @@
+using Microsoft.Xna.Framework;
+
+namespace Barotrauma
+{
+    interface ISpatialEntity
+    {
+        Vector2 Position { get; }
+        Vector2 WorldPosition { get; }
+        Vector2 SimPosition { get; }
+        Submarine Submarine { get; }
+    }
+}