[GIE/Engine] Pegasus cluster config files should support hostname instead of only IP

[MeloYang05]

Is your feature request related to a problem? Please describe. In GraphScope's current version, starting a pegasus cluster needs to know all servers' IPs. It is not friendly in a cloud-native environement. For example, if we want to start a pegasus cluster with kubernates, we have to use kubernates' dns server to know each server's IP and edit the config toml file in each container before starting the cluster. It is not only inconvenient but also ugly. Therefore, I strongly recommended to support using hostname in pegasus cluster's config file.

Describe the solution you'd like Support using hostname in pegasus cluster's config file. E.g., we can write localhost in the toml file instead of 127.0.0.1. current requirement:

[[network.servers]]
ip = '127.0.0.1'
port = 11234

expected one:

[[network.servers]]
ip = 'localhost'
port = 11234