Remove EntityNetworkUtils, move extension methods to AtmosDirection class.

Content.Shared/Atmos/AtmosDirection.cs

@@ -142,6 +142,28 @@ namespace Content.Shared.Atmos
         {
             return (direction & other) == other;
         }
+
+        public static Vector2i CardinalToIntVec(this Direction dir)
+        {
+            switch (dir)
+            {
+                case Direction.North:
+                    return new Vector2i(0, 1);
+                case Direction.East:
+                    return new Vector2i(1, 0);
+                case Direction.South:
+                    return new Vector2i(0, -1);
+                case Direction.West:
+                    return new Vector2i(-1, 0);
+                default:
+                    throw new ArgumentException($"Direction dir {dir} is not a cardinal direction", nameof(dir));
+            }
+        }
+
+        public static Vector2i Offset(this Vector2i pos, Direction dir)
+        {
+            return pos + dir.CardinalToIntVec();
+        }
     }
 
     public sealed class AtmosDirectionFlags { }