[Audio] About pan parameter for sound effect

[Demonese]

I started the LuaSTG Sub (LuaSTG Ex Plus Next) project in 2020, but these codes already existed in earlier THlib and Editor versions:

1. strange legacy code from THlib
   
2. LuaSTG Editor Sharp/SharpX generated code (please pay attention to the self.x/256)
   

I think this is equivalent to disabling the pan parameter.

Why? I don't know.

If your project does require pan parameter, please remember to modify THlib and LuaSTG Editor Sharp/SharpX.

Also see: #71