Add Geo IP lookup based proximity matching

[Maxopoly]

Would allow detecting possible alts on new cable connections

[MrXFier]

Not sure if this is a good use of our time. We should instead be looking at updating civ mods to our current server version.

[Maxopoly]

It's at the lowest possible priority in our issue tracking https://github.com/orgs/CivClassic/projects/4