chore(models): streamline all server models IPs (#942)

- Use `IPs []net.IP` for all server models
- Use `ips` JSON field for all server models
- Merge IPv4 and IPv6 addresses together for Mullvad

internal/updater/providers/privado/location.go

@@ -11,9 +11,9 @@ import (
 
 func setLocationInfo(ctx context.Context, client *http.Client, servers []models.PrivadoServer) (err error) {
 	// Get public IP address information
-	ipsToGetInfo := make([]net.IP, len(servers))
-	for i := range servers {
-		ipsToGetInfo[i] = servers[i].IP
+	ipsToGetInfo := make([]net.IP, 0, len(servers))
+	for _, server := range servers {
+		ipsToGetInfo = append(ipsToGetInfo, server.IPs...)
 	}
 	ipsInfo, err := publicip.MultiInfo(ctx, client, ipsToGetInfo)
 	if err != nil {