feat(fastestvpn): update servers data using API instead of zip file

- Add city filter
- More dynamic to servers updates on fastestvpn's end
- Update servers data

internal/provider/fastestvpn/updater/servers.go

@@ -4,48 +4,26 @@ import (
 	"context"
 	"fmt"
 	"sort"
-	"strings"
 
 	"github.com/qdm12/gluetun/internal/models"
 	"github.com/qdm12/gluetun/internal/provider/common"
-	"github.com/qdm12/gluetun/internal/updater/openvpn"
 )
 
 func (u *Updater) FetchServers(ctx context.Context, minServers int) (
 	servers []models.Server, err error) {
-	const url = "https://support.fastestvpn.com/download/fastestvpn_ovpn"
-	contents, err := u.unzipper.FetchAndExtract(ctx, url)
-	if err != nil {
-		return nil, err
-	} else if len(contents) < minServers {
-		return nil, fmt.Errorf("%w: %d and expected at least %d",
-			common.ErrNotEnoughServers, len(contents), minServers)
-	}
-
+	protocols := []string{"tcp", "udp"}
 	hts := make(hostToServer)
 
-	for fileName, content := range contents {
-		if !strings.HasSuffix(fileName, ".ovpn") {
-			continue // not an OpenVPN file
-		}
-
-		country, tcp, udp, err := parseFilename(fileName)
+	for _, protocol := range protocols {
+		apiServers, err := fetchAPIServers(ctx, u.client, protocol)
 		if err != nil {
-			u.warner.Warn(err.Error())
-			continue
+			return nil, fmt.Errorf("fetching %s servers from API: %w", protocol, err)
 		}
-
-		host, warning, err := openvpn.ExtractHost(content)
-		if warning != "" {
-			u.warner.Warn(warning)
+		for _, apiServer := range apiServers {
+			tcp := protocol == "tcp"
+			udp := protocol == "udp"
+			hts.add(apiServer.hostname, apiServer.country, apiServer.city, tcp, udp)
 		}
-		if err != nil {
-			// treat error as warning and go to next file
-			u.warner.Warn(err.Error() + " in " + fileName)
-			continue
-		}
-
-		hts.add(host, country, tcp, udp)
 	}
 
 	if len(hts) < minServers {