Remove all use of `developer` cvar from QC
Debugging messages are made less useful by having them enabled for all 3 VMs and DP in a single cvar. Generally someone is working on one of the VMs or the engine and it's just too much spam, resulting in a need to add or edit debug prints even where they already exist. IMO each QC VM's debug messages should be usable independently.
The menu uses developer
to hide "advanced" or "WIP" options. This is unrelated to debug prints (which also have a perf cost) so this should use a separate menu_
cvar.