Fix: Event initialization

Comparisons where wrong, object type id setting was missing
Add finalization for event messages
Add keys for event deserialization
Add states for event deserialization
Add map key transitions for event deserialization
Add support for event name deserialization
Add support for simple values (directly embedded in the JSON)
Add simple test for event deserialization
Add test for event with only event type set
Add test for deserializing a complete event