placeholder player models and better syncing

-Created monolith-like model for players to see each other.
-Re-organized the file structure of rendering files to better reflect
what they are for.
-Refactored worldFunction entity creation and removal to be more concise
and more reusable.
-Now performing proper player position/velocity syncing with the server and
now two players can see each other in real time.
-Player entity is created when the player makes a server connectiona and is
destroyed when the connection is lost.