[Feature] Offline player markers

[McSnurtle]

Describe the feature

Players, once logged out, would have a grayscale version of their player icon stuck to the worldmap indicating where they were when they logged out.

What problems does this feature solve / cause?

Solves not knowing who, where, when, and what?? 👀

Which pre-existing system does this feature tie into?

UI, Other

Additional context

https://github.com/TechnicJelle/BlueMapOfflinePlayerMarkers

[McSnurtle]

This would allow players to set AFK traps - however seemingly unlikely, it would most certainly happen at some point. Like #385 , I will run a poll.