Support multiple comma-separated IPs per host in split tunneling

[ilyachase]

A bit hacky, but a minimal non-bc-breaking solution to support multiple IPs per hostname.

Changes

• Collect all IPs from hostname resolution instead of stopping at the first IP
• Store multiple resolved IPs as comma-separated strings when adding hostnames
• Parse comma-separated IP strings from settings and import/export
• Support multiple IPs per host in split tunneling

Testing

• ✅ Tested on bbc.com IPs: 151.101.128.81,151.101.192.81,151.101.64.81,151.101.0.81
• ✅ Non-first IPs (e.g., 151.101.64.81) accessible through VPN
• ✅ Selective split tunneling works correctly
• ✅ Import/Export functionality preserved

Import/Export Format

The feature supports comma-separated IPs in the import/export JSON format:

[
    {
        "hostname": "bbc.com",
        "ip": "151.101.0.81,151.101.64.81,151.101.128.81,151.101.192.81"
    }
]

UI preview

Fixes

Resolves #1750