The status logger itself is already globally accessible through the controller,
which is actually UB because the `StatusLogger` is not `Sync`. By making the
status logger's state global, we can later make the status logger itself
non-global.

This fixes the UB where `StatusLogger` is shared between threads but is not
`Sync`.

It may sometimes take many real seconds to simulate one shadow second, so by
showing milliseconds in the simulation time we can see that the simulation time
is still advancing.