Entities/Object: Add some Position const& overloads to distance/angle methods for usability.

src/server/game/Entities/Object/Position.cpp

@@ -71,12 +71,12 @@ Position Position::GetPositionWithOffset(Position const& offset) const
     return ret;
 }
 
-float Position::GetAngle(const Position* obj) const
+float Position::GetAngle(Position const* pos) const
 {
-    if (!obj)
+    if (!pos)
         return 0;
 
-    return GetAngle(obj->GetPositionX(), obj->GetPositionY());
+    return GetAngle(pos->GetPositionX(), pos->GetPositionY());
 }
 
 // Return angle in range 0..2*pi