Add enhanced port handling support

[sahmadiut]

This Pull Request introduces support for handling multiple port mapping formats, providing greater flexibility in port configurations:

• "443": Maps the local port to the same remote port.
• "443=443": Explicitly maps the local port to a remote port.
• "[1000:1003]": Maps a range of ports to themselves sequentially.
• "[1000:1003]=5201": Maps a range of local ports to a single remote port.

These updates allow for more dynamic and flexible configuration of ports, making it easier to handle different use cases.

[sahmadiut]

Adding to the existing port mapping improvements, this update introduces support for two additional formats and enhances error handling:

New supported formats:

• "1000:1003": Maps a range of ports to themselves sequentially (without brackets).
• "1000:1002=5201": Maps a range of local ports to a single remote port (without brackets).

Key improvements:

Implemented regex-based parsing for more robust and flexible port mapping. Enhanced error management for invalid port mappings, providing better feedback and stability.

[Musixal]

Unfortunately, I haven't had a chance to read your PR yet. But I think that using regex reduces the readability of the code. Also, in my opinion, the format of a port range is better to be like this: 1001-1003. What we also see in HAProxy.

[sahmadiut]

Thank you for your feedback! I appreciate your point about readability