[Feature] Disable spectator mode block no-clip

[elhertz]

WIP: i intend to (at some point) add a adventure-mode-like visitor mode, so players can interact with other players while not being able to interact with the world

Hi! Some time ago I discovered a vanilla bug where you could be in a spectator mode without being able to go through blocks (kinda like a pseudo spectator/creative mode). So far I couldn't replicate it but I thought it could be possible to recreate it with mods somehow. Later I found this in a quick google search.
I don't know anything about code and maybe spigot is too different from fabric but I hope you can find this helpful.