* Asynchronous repeatResolve
* Parallel cyberghost and PIA (v3) processing, with a 10 goroutines limit
* Add missing vyprvpn cli flag to updater
* Increase DNS repetitions to 5 in order to obtain more IP addresses
* Update old PIA IP addresses
* Add Surfshark servers by API (unused for now)
* Updater loop with period and http route
* Using DNS over TLS to update servers
* Better logging
* Remove goroutines for cyberghost updater
* Respects context for servers update (quite slow overall)
* Increase shutdown grace period to 5 seconds
* Update announcement
* Add log lines for each provider update start
* Adapt storage: SyncServers write to file option, export FlushToFile
* CLI built-in updater for old and new PIA servers
* Update hardcoded IP addresses for PIA old and new servers
* Add PIA old to allServers struct and update timestamps
* Adapt code to work with new and old PIA servers
* Remove PIA subdomains (unneeded) from resolver tool