Multi-Proxy Support for FRPS Port: Enhancing Performance and Scalability

## Feature Request
We appreciate the excellent work of the software development team. To further improve the user experience and performance of the FRPS system, we kindly request the addition of a feature that allows multiple STC proxies to be bound to the same FRPS port. This functionality would be highly beneficial and is reminiscent of the capabilities offered by SSH multiplexers.

## Alternatives Considered
We would like to express our gratitude for the great project that has been developed. In considering alternative solutions, we believe that the ability to bind multiple proxies to a single port would be a significant enhancement to the existing system.

## Affected Area
The proposed feature would have a positive impact on the following areas:

* **Performance and Scalability**: By allowing multiple proxies to share a single port, the system would be able to handle a greater number of connections, leading to improved performance and scalability.
* **User Experience**: This feature would provide users with a more streamlined and efficient experience, as they would be able to manage multiple proxies from a single interface.