feat(Tech: Spawn): Reduce amount of data passed in spawn info requests

[Kruptein]

The socket event Location.Spawn.Info.Get was receiving all shape information for the related spawn objects, although only the location and some id/name info was needed.

This PR also cleans up a couple of related concepts:

• The aforementioned socket event no longer uses a separate return event, but uses the event callback that socket.io provides
• server Shape now has a proper getter and setter for center
• server Shape subtype center offset no longer requires unused x,y arguments
• PositionTuple uses floats instead of ints