net/qrcp: add port: Transfer files over wifi by scanning a QR code

Transfer files over Wi-Fi from your computer to a mobile device by
scanning a QR code without leaving the terminal.

qrcp binds a web server to the address of your Wi-Fi network interface
on a random port and creates a handler for it. The default handler
serves the content and exits the program when the transfer is
complete. When used to receive files, qrcp serves an upload page and
handles the transfer.

WWW: https://claudiodangelis.com/qrcp