Support online port checkers

[Measurity]

Describe the issue

Users want to verify they port forwarded correctly by using port checkers. Add a view to the launcher for users to test a port is open.

After implementation, verify by using some port checkers like:

• https://www.ipvoid.com/udp-port-scan/
• https://pentest-tools.com/network-vulnerability-scanning/udp-port-scanner-online-nmap

For port checkers to work, use your public IP: https://ipv4.icanhazip.com/

Proof of concept

Following code should show Open status in port checkers for port 11000 UDP.

using UdpClient client = new(new IPEndPoint(IPAddress.Any, 11000));
Console.WriteLine("Ready to receive stuff!");
while (true)
{
    var result = await client.ReceiveAsync();
    Console.WriteLine($"{result.RemoteEndPoint} - {result.Buffer.Length} bytes: {BitConverter.ToString(result.Buffer).Replace('-', '\0')}");
    await client.SendAsync(result.Buffer, result.Buffer.Length, result.RemoteEndPoint);
}

[OhmV-IR]

Currently taking on this issue, but I haven't made a PR yet. Have created a branch in my fork of the nitrox repo