Handle different cluster latencies

[voltbit]

This is an issue that spans multiple parts of the system

• The redis-cli commands have a hardcoded context timeout, this should account for different cluster latencies, as some commands such as --cluster add-node can take a long time.
  • https://github.com/PayU/redis-operator/blob/master/controllers/rediscli/redis_cli.go#L26
  • One way to handle this would be to measure the latency using a ping message and then set the timeout based on it