Selection of Speedtest server should rely on Speedtest rather than IP whois lookup

[hrxcodes]

Describe the feature

Selection of Speedtest server should rely on Speedtest rather than IP whois lookup.
There were some discussions on IRC how this should be handled bc users had slaves in environments where the neither the pasv_addr was set or in the config. This would only make sense in a testing scenario so not sure about the usecase here.

Either way the current evaluation of what server to use is over engineered.

Suggestion

As discussed on IRC we should instead query the service to tell us what the closest server is.
For example by using this api and speedtest wil tell us the closest server based on the egress IP information that Speedtest seems the connection from, no matter if the slave is on a CGNAT, NAT, local docker network or has a public external IP