Kafka-on-Pulsar MVP

[sijie]

• General:
  • Framework
  • Integration Test
  • CI Enable checkstyle and spotbugs #6
  • Checkstyle & spotbugs : Enable checkstyle and spotbugs #6
  • Utils: Port delayed operations implementation from Kafka #22 Port Kafka timer classes #21
• Protocol:
  • Produce Request produce implementation #14
  • Consume Request Fetch implementation #19
  • Transaction
  • Coordinator Group metadata manager & coordinator #23
    • Group
      • Group & Member Metadata Kafka coordinator service (part 1): Add GroupMetadata and MemberMetadata #15
      • Offsets Add offset metadata to group metadata #24

[sijie]

@jiazhai Let's fill up the list of features to implement for KOP MVP.