Add `dispatcher` class (empty function bodys)
Implement `dispatcher::map_from_event_values()` function
This function maps `event_values` to dispatcher internal `dispatcher_events`.
Add unit test class for dispatcher
This class currently just test the mapping of `event_values` to `dispatcher_events`.
Implement register and unregister functions of the `dispatcher`
Merge branch 'topic/dispatcher' into topic/fsm

Conflicts:
	se2p_2_3/src/lib/constants.hpp