Redis Sentinel ip address/hostname mapping config

[elimelt]

Motivation

It would be really helpful if we could map the ip/hostname sentinel responds with to a custom address for testing/proxying, like how redis cluster supports nodeAddressMap

I can open a PR if this is an acceptable feature to add

Basic Code Example

createSentinel({
  ...
  nodeAddressMap: {
    '10.0.0.1:30001': {
      host: 'external-host.io',
      port: 30001
    },
    '10.0.0.2:30002': {
      host: 'external-host.io',
      port: 30002
    }
  }
}