Add --name option to display custom names for hosts

[Alec-Dieken]

This PR adds a new --name feature that allows users to specify custom display names for hosts being pinged.
This makes it easier to identify targets in the graph, especially when monitoring multiple similar IPs or when the hostname isn't descriptive enough.

Feature Details

• Added a new --name command line option that can be used multiple times
• Each --name corresponds to a host in the same order they're specified on the command line
• Custom names are displayed in the format: Custom Name (IP Address)
• Falls back to the original hostname display if no custom name is provided
• Works seamlessly with existing features like cloud shorthands and IPv4/IPv6 options

Example Usage

Specify custom names for hosts

gping --name "Google DNS" 8.8.8.8 --name "Cloudflare DNS" 1.1.1.1

Mix named and unnamed hosts

gping --name "Production DB" 10.0.0.5 10.0.0.6 10.0.0.7