Up until now, nymea would generate EventTypes for every StateType
as well as emit an Event (along with a StateChanged notification) for
every change. This results in a lot of duplicated network traffic
which is of not much use. The StateChanged notification contains
all the information in the Event too and nymea:app actually never
really used Events for state changes.
This commit removes the events from the ThingClass, making it a lot
smaller and stops emitting Events for state changes.
As this is breaking the behavior, the JSONRPC API major version
is bumped.
