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/common/updater.go

@@ -6,6 +6,7 @@ import (
 	"net"
 
 	"github.com/qdm12/gluetun/internal/models"
+	publicipmodels "github.com/qdm12/gluetun/internal/publicip/models"
 	"github.com/qdm12/gluetun/internal/updater/resolver"
 )
 
@@ -28,3 +29,7 @@ type Unzipper interface {
 type Warner interface {
 	Warn(s string)
 }
+
+type IPFetcher interface {
+	FetchMultiInfo(ctx context.Context, ips []net.IP) (data []publicipmodels.IPInfoData, err error)
+}