feat(nordvpn): update mechanism uses v2 API

internal/provider/nordvpn/updater/api.go

@@ -13,35 +13,32 @@ var (
 )
 
 func fetchAPI(ctx context.Context, client *http.Client,
-	recommended bool, limit uint) (data []serverData, err error) {
-	url := "https://api.nordvpn.com/v1/servers"
-	if recommended {
-		url += "/recommendations"
-	}
+	limit uint) (data serversData, err error) {
+	url := "https://api.nordvpn.com/v2/servers"
 	url += fmt.Sprintf("?limit=%d", limit) // 0 means no limit
 
 	request, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
 	if err != nil {
-		return nil, err
+		return serversData{}, err
 	}
 
 	response, err := client.Do(request)
 	if err != nil {
-		return nil, err
+		return serversData{}, err
 	}
 	defer response.Body.Close()
 
 	if response.StatusCode != http.StatusOK {
-		return nil, fmt.Errorf("%w: %s", ErrHTTPStatusCodeNotOK, response.Status)
+		return serversData{}, fmt.Errorf("%w: %s", ErrHTTPStatusCodeNotOK, response.Status)
 	}
 
 	decoder := json.NewDecoder(response.Body)
 	if err := decoder.Decode(&data); err != nil {
-		return nil, fmt.Errorf("decoding response body: %w", err)
+		return serversData{}, fmt.Errorf("decoding response body: %w", err)
 	}
 
 	if err := response.Body.Close(); err != nil {
-		return nil, err
+		return serversData{}, err
 	}
 
 	return data, nil