The JSON encoding should only be used for debugging purposes! However
this change avoids showing errors in case there are unknown fields in the
JSON payload. This would happen when for example the MQTT Forwarder
and ChirpStack uses a different API version (which in case of Protobuf
would be fine, as long as the major version remains the same).
This reduces the amount of dependencies in case not all features are
being used. E.g. tonic is only needed if using gRPC and pbjson,
pbjson-types and serde are only needed if using the JSON serialization.
This makes it possible for external services to subscribe (through
Redis) for realtime events. E.g. a create, update or delete device event
could trigger an external synchronization.
