Initial support for network metrics.
Fixed chunk cache region notification of chunks becoming available.
Clients can now see their inventory - items are replicated to their owners.
Removed GameType system, as it wasn't suitable for networking as is.
Started adding a net rate to limit replication per second
Fixed block items (apparently prefab inheritance only works for one level at the moment)
Implemented basic network support for UseItem and Attack
Added some support around block entity replication
Restricted client events to only be propagated when sent to owned entities
Some optimisation to network messages - replaced use of strings for component/event and field names with ids.