extend central state monitor
There are two issues with the state machines of modules:
- automatic transition to next condition in the experiment manager should depend on the combined state of all modules, but is currently broken
- the enabling of the state change buttons in JOAN HQ should depend on the combined states of all modules, it currently depends only on the last module that had a state change and ignores the others
Both of these issues can be fixed by keeping track of the combined states of the modules in the central state monitor. This should be implemented.