Update ZooKeeper URLManager implementations to use registry client service

There are multiple ZooKeeper-based URLManager implementations:

• BaseZookeeperURLManager extensions
  • KafkaZooKeeperURLManager
  • HBaseZooKeeperURLManager
  • SOLRZooKeeperURLManager
• HS2ZooKeeperURLManager

These should all be updated to support using clients from the remote configuration registry client service.

Either a single well-known client name can be relied upon by all of these implementations, or there could be a configuration property for each implementation, binding it to a ZooKeeper client.

Careful consideration should be given to the backward-compatibility requirements around continued support for the current configuration model.