feat(netxlite): implements NS queries (#734)

This diff has been extracted from eb0bf38957.

See https://github.com/ooni/probe/issues/2096.

While there, skip the broken tests caused by issue
https://github.com/ooni/probe/issues/2098.

internal/engine/netx/resolver/cache.go

@@ -25,7 +25,7 @@ func (r *CacheResolver) LookupHost(
 	if err != nil {
 		return nil, err
 	}
-	if r.ReadOnly == false {
+	if !r.ReadOnly {
 		r.Set(hostname, entry)
 	}
 	return entry, nil