Add “Open to LAN” toggle for container RDP port binding

[Bl4ckk98]

Add a new container.openToLan boolean (default false) stored in config. When enabled, generated compose files omit the 127.0.0.1 bind prefix so RDP port is exposed on all host interfaces. Includes UI toggle in Settings -> Container.

Why: I needed it for work purposes and I thought somebody else would benefit from it.

Testing phase done on Podman:

• Default (openToLan=false):
• Regenerate compose: all ports have 127.0.0.1:...
• From another device in the same LAN I can't reach :<RDP_PORT>
• Active (openToLan=true):
• Regenerate compose: 127.0.0.1 is no more present for RDP
• From another device in the same LAN I can reach :<RDP_PORT>
• Upgrade scenario: starting from an old config file without openToLan, it gets populated without issues.

Thoughts for the future:

• I don't know if it's better to do the same for the other ports, but I never felt the need.
• Everytime I need to check what is the current RDP port. It surely is not an issue to get it and it's quite a "nerdy" newer option, but I think the RDP port should be displayed in the config page.