Add a layer to choose which IP-service can be used

[Alexander Kellner]

At the moment only ip-api.com is hardcoded. Of course this can be turned off, but there is no possibility to use a different service or to modify the URL (http://ip-api.com for free use and https://ip-api.com for payed access).
I think of a layer were one or more services can be registered with a modifier class for value preperation.

E.g. https://iplist.cc/api/52.178.167.109 would be an alternative service to ip-api.com. This service is not so accurate then ip-api but it's completely free and requests are made with port 443

I think we should offer both services per default.