Make Entities lightweight

[GregHib]

Might be worth reconsidering:

• How ChunkUpdate's are stored for entities
• How owner's are handled
• If Event's is necessary for all entities Improve event handling #324
• Converting most entities to Record's

Floor item state, respawn handling will be harder without tracking event's
GameObjects also handling respawning and temp replacing

Main gain to be made is faster map loading when GameObject's don't take as long to create. (750ms -> 150ms with cache)

[GregHib]

Removed Events and Size from Entity so it's now only Tile.

Objects are now lightweight #345

FloorItems wasn't possible as they require an owner, and the owner must be stored as a string as a player logging back in can end up with a different index.