chore(publicip): refactoring

- Exported `Fetcher` interface
- Inject `Fetcher` to publicip loop and updaters
- Get public IP and information at the same time
- Only query ipinfo.io
- Make `MultiInfo` part of the `Fetch` object

internal/provider/purevpn/updater/servers.go

@@ -11,7 +11,6 @@ import (
 
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/common"
-	"github.com/qdm12/gluetun/internal/publicip"
 	"github.com/qdm12/gluetun/internal/updater/openvpn"
 )
 
@@ -83,7 +82,7 @@ func (u *Updater) FetchServers(ctx context.Context, minServers int) (
 	for i := range servers {
 		ipsToGetInfo[i] = servers[i].IPs[0]
 	}
-	ipsInfo, err := publicip.MultiInfo(ctx, u.client, ipsToGetInfo)
+	ipsInfo, err := u.ipFetcher.FetchMultiInfo(ctx, ipsToGetInfo)
 	if err != nil {
 		return nil, err
 	}