Player should be invisible when in pre-respawn stage.

**Is your feature request related to a problem? Please describe.**
When player is in pre-respawn stage,they won't get insivible effect in their view as that in Hypixel.

**Describe the solution you'd like**
Add insivible effect to player in pre-respawn stage.

**Describe alternatives you've considered**
Just set player in pre-respawn stage as spectator in order to get them insivible effect.