refactor: spin geoipx off geolocate (#893)

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

internal/tracex/archival.go

@@ -13,7 +13,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/ooni/probe-cli/v3/internal/engine/geolocate"
+	"github.com/ooni/probe-cli/v3/internal/geoipx"
 	"github.com/ooni/probe-cli/v3/internal/model"
 	"github.com/ooni/probe-cli/v3/internal/netxlite"
 )
@@ -201,7 +201,7 @@ func (qtype dnsQueryType) makeAnswerEntry(addr string) DNSAnswerEntry {
 	answer := DNSAnswerEntry{AnswerType: string(qtype)}
 	// Figuring out the ASN and the org here is not just a service to whoever
 	// is reading a JSON: Web Connectivity also depends on it!
-	asn, org, _ := geolocate.LookupASN(addr)
+	asn, org, _ := geoipx.LookupASN(addr)
 	answer.ASN = int64(asn)
 	answer.ASOrgName = org
 	switch qtype {