A bunch of packages (including oohelperd) just need the ability to
use MaxMind-like databases. They don't need the additional functionality
implemented by the geolocate package. Such a package, in fact, is
mostly (if not only) needed by the engine package.
Therefore, move code to query MaxMind-like databases to a separate
package, and avoid depending on geolocate in all the packages for
which it's sufficient to use geoipx.
Part of https://github.com/ooni/probe/issues/2240
These two small packages could easily be merged into the model
package, since they're clearly model-like packages.
Part of https://github.com/ooni/probe/issues/2115
Cloudflare hosted services provide a certain service of `/cdn-cgi/trace` with their base url (for example, `www.cloudflare.com` or `www.nginx.com`), which can be used to obtain `ip` in the probe's `geolocate` feature.
The same feature was added in this pr, hence, increasing the number of `baseURL`s in `geolocate`.
Co-authored-by: Simone Basso <bassosimone@gmail.com>
