[feat] discovery.HostNode() should accept configs rather than read env directly

[qazwsxedckll]

Reading and merging env to configs should be handled by user using some modules like viper or koanf.

To my opinion, I always avoid using env and put all configs in local config files. I have come accross many times that a mysterious env is controlling a key feature and no one knows about it. It is a nightmare to debug.

[Tochemey]

Thanks for the suggestion. I will look into it. However there are no hidden env vars and there are all documented only few used for cluster run.