Fix `spectatorPlayersUsePortals` not showing portal nausea affect when `portalSpectatorDelay` is at a value greater than 1

[Gilly7CE]

When the server side player entity moves into a nether portal it will now send a packet to the client telling it to set the client side player to be inside a nether portal block. This will then allow the portal nausea animation to play.

Fixes #126