KafkaConsumer need to be closed

`offsetGen.getNextOffsetRanges` will is called periodically in DeltaStreamer application, and it will `new KafkaConsumer(kafkaParams)` without close, and Exception will throw after a while.

```
java.net.SocketException: Too many open files
at sun.nio.ch.Net.socket0(Native Method)
at sun.nio.ch.Net.socket(Net.java:411)
at sun.nio.ch.Net.socket(Net.java:404)
at sun.nio.ch.SocketChannelImpl.<init>(SocketChannelImpl.java:105)
at sun.nio.ch.SelectorProviderImpl.openSocketChannel(SelectorProviderImpl.java:60)
at java.nio.channels.SocketChannel.open(SocketChannel.java:145)
at org.apache.kafka.common.network.Selector.connect(Selector.java:211)
at org.apache.kafka.clients.NetworkClient.initiateConnect(NetworkClient.java:864)
at org.apache.kafka.clients.NetworkClient.ready(NetworkClient.java:265)
at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.trySend(ConsumerNetworkClient.java:485)
at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:261)
at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:242)
at org.apache.kafka.clients.consumer.internals.ConsumerNetworkClient.poll(ConsumerNetworkClient.java:218)
at org.apache.kafka.clients.consumer.internals.Fetcher.getTopicMetadata(Fetcher.java:274)
at org.apache.kafka.clients.consumer.KafkaConsumer.partitionsFor(KafkaConsumer.java:1774)
at org.apache.kafka.clients.consumer.KafkaConsumer.partitionsFor(KafkaConsumer.java:1742)
at org.apache.hudi.utilities.sources.helpers.KafkaOffsetGen.getNextOffsetRanges(KafkaOffsetGen.java:177)
at org.apache.hudi.utilities.sources.JsonKafkaSource.fetchNewData(JsonKafkaSource.java:56)
at org.apache.hudi.utilities.sources.Source.fetchNext(Source.java:73)
at org.apache.hudi.utilities.deltastreamer.SourceFormatAdapter.fetchNewDataInRowFormat(SourceFormatAdapter.java:107)
at org.apache.hudi.utilities.deltastreamer.DeltaSync.readFromSource(DeltaSync.java:288)
at org.apache.hudi.utilities.deltastreamer.DeltaSync.syncOnce(DeltaSync.java:226)
```