Add feature to request consumer group information

[Ledostuff]

Add feature to request consumer group information(start, end offsets, lags, consumer-instance-id, consumer-instance-ip) Added rest paths:

1. /groups - returns consumer groups list

[{"groupId":"perf-consumer-46894","coordinator":{"host":"{some_host_name}","port":9496}}]

2. /groups/{groupId}/topics - returns topics for wich group is subscribed

[{"name":"1"}]

3. /groups/{groupId}/topics/{topic} - returns consumer group information(start, end offsets, lags, consumer-instance-id, consumer-instance-ip...) restricted by spesified topic

{"topicPartitionList":[{"consumerId":"consumer-1-88792db6-99a2-4064-aad2-38be12b32e88","consumerIp":"/{some_ip}","topicName":"1","partitionId":0,"currentOffset":15338734,"lag":113812,"endOffset":15452546},{"consumerId":"consumer-1-88792db6-99a2-4064-aad2-38be12b32e88","consumerIp":"/{some_ip}","topicName":"1","partitionId":1,"currentOffset":15753823,"lag":136160,"endOffset":15889983},{"consumerId":"consumer-1-88792db6-99a2-4064-aad2-38be12b32e88","consumerIp":"/{some_ip}","topicName":"1","partitionId":2,"currentOffset":15649419,"lag":133052,"endOffset":15782471}],"topicPartitionCount":3,"coordinator":{"host":"{coordinator_host_name}","port":9496}}

4. /groups/{groupId}/partitions - returns consumer group information(start, end offsets, lags, consumer-instance-id, consumer-instance-ip...) for all topics for wich group is subscribed

{"topicPartitionList":[{"consumerId":"consumer-1-88792db6-99a2-4064-aad2-38be12b32e88","consumerIp":"/{some_ip}","topicName":"1","partitionId":0,"currentOffset":15338734,"lag":113812,"endOffset":15452546},{"consumerId":"consumer-1-88792db6-99a2-4064-aad2-38be12b32e88","consumerIp":"/{some_ip}","topicName":"1","partitionId":1,"currentOffset":15753823,"lag":136160,"endOffset":15889983},{"consumerId":"consumer-1-88792db6-99a2-4064-aad2-38be12b32e88","consumerIp":"/{some_ip}","topicName":"1","partitionId":2,"currentOffset":15649419,"lag":133052,"endOffset":15782471}],"topicPartitionCount":3,"coordinator":{"host":"{coordinator_host_name}","port":9496}}

Add unit and integration tests