gnmic supports exporting subscription updates to multiple Apache Kafka brokers/clusters simultaneously

A Kafka output can be defined using the below format in gnmic config file under outputs section:

    - type: kafka # required
      address: localhost:9092 # comma separated brokers addresses
      topic: telemetry # topic name
      max-retry: # max number of retries retry
      timeout: # kafka connection timeout

Currently all subscriptions updates (all targets and all subscriptions) are published to the defined topic name