[pulsar-client-cpp]Change state_ to closed when resultOk is returned

[hrsakai]

Motivation

• Consumer retry the connection forever even though Consumer::close() is called in following case.

1. Consumer connects to broker
2. Revoke the consumer's permission to consume(e.g. pulsar-admin namespaces revoke-permission --role "consumer.role" public/global/n1)
3. Execute Consumer.Close()

• Closed seems to be better when ResultOk is returned in {ProducerImpl,ConsumerImpl}::closeAsync().

Modifications

• Change state_ to Closing at the start of closing process in ConsumerImpl::closeAsync().
• Change state_ to Closed when ResultOk is returned in {ProducerImpl,ConsumerImpl}::closeAsync()

[hrsakai]

rerun cpp tests

[hrsakai]

rerun java8 tests