Server - replace serilog with something better

[cdhanna]

ZLogger is the winner from our investigation! Justin is doing it on the ProtoActor stack, so talk to him for support.
Logs need to be compatible with whatever our log target is, (Signoz?) or Cloud Watch (today), or whatever.

At runtime, per realm, you need to be able to control the log level.

Logs should also have categories, or be tagged with playerId, realm, route.