fix(pd): resolve hostname entries in IpAuthHandler allowlist

[bitflicker64]

Purpose of the PR

• fix [Bug] IpAuthHandler blocks all cross-node raft connections in Docker bridge mode — hostname vs IP mismatch #2960

IpAuthHandler only compared the client IP with the allowlist entries directly.
When the allowlist contains hostnames, connections from their resolved IPs could be rejected.

Main Changes

• Resolve hostname allowlist entries using InetAddress.getAllByName
• Store resolved addresses in a set used for connection validation
• Keep runtime validation as a simple Set.contains() lookup

Verifying these changes

• Trivial rework / code cleanup without any test coverage. (No Need)
• This issue was identified while testing changes in PR fix(docker): migrate single-node compose from host to bridge networking #2952.

Does this PR potentially affect the following parts?

• Dependencies
• Modify configurations
• The public API
• Other affects
• Nope

Documentation Status

• Doc - TODO
• Doc - Done
• Doc - No Need