Support horizontal scaling

• Put revision consumer service in consumer group and set up manual acknowledgement
• Switch from gRPC to Dubbo which support customized load balancing
• Implement the routing logic for broadcast service, which support scaling in/out without affecting connected clients

Collaborative editing on spreadsheet

1.1.0

feat(core): implement command execution for json type

Basic functions

1.0.0

feat(broadcast): implement broadcast service as a grpc service