[3.x] Support RadminVPN and/or manual network choosing

[rozsazoltan]

The software can transmit the screen over an internal network. In addition to functioning as a Virtual Display on your internal WiFi or LAN network, (idea:) an option could be added for manual network selection.

This way, with the support of the free RadminVPN installed alongside the software, you could share your screen with people on different networks, including friends and acquaintances.

[rozsazoltan]

If the application's port is allowed through the firewall on your network, it will work without any issues. The currently requested development focuses on expanding the range of detected networks:

• listing all connected networks,
• possibly allowing unique port configuration per network,
• and the option to assign a custom PIN (or enable random PIN generation).