Remove no longer used `--data-port` & associated options

[JaroslavTulach]

• Replace language server WebSocket connection with Ydoc #14438 got integrated, but
• when running enso --help I still see:

    --data-port <data-port>                Data port for visualization
                                           protocol

    --secure-data-port <data-port>         A secure data port for
                                           visualization protocol
    --secure-rpc-port <rpc-port>           A secure RPC port for
                                           processing all incoming
                                           connections

• the --data-port is replaced by YjsChannel and can be removed
• according to @4e6, we still need --rpc-port for health check and maybe some other tasks
• when at it: document description of the ydoc-server port value in the enso --help output!

Originally posted by @JaroslavTulach in #14438 (comment)