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/updater.go

@@ -1,22 +1,20 @@
 package updater
 
 import (
-	"net/http"
-
 	"github.com/qdm12/gluetun/internal/provider/common"
 )
 
 type Updater struct {
-	client           *http.Client
+	ipFetcher        common.IPFetcher
 	unzipper         common.Unzipper
 	parallelResolver common.ParallelResolver
 	warner           common.Warner
 }
 
-func New(client *http.Client, unzipper common.Unzipper,
+func New(ipFetcher common.IPFetcher, unzipper common.Unzipper,
 	warner common.Warner, parallelResolver common.ParallelResolver) *Updater {
 	return &Updater{
-		client:           client,
+		ipFetcher:        ipFetcher,
 		unzipper:         unzipper,
 		parallelResolver: parallelResolver,
 		warner:           warner,