feat(network): added local port forwarding

[grampelberg]

• To get this working correctly, the data and state management in session needed to be refactored. This is because tcpip requests create new channels on top of the initial one used via pty requests. Now the state stops at Authenticated and the functions themselves hold their own state (like russh_sftp taking ownership of the channel).
• Error handling is a little tricky, there's no way to return an error on the incoming tcpip channel (no idea what the protocol is after all). So, it is possible to broadcast to a writer from anywhere in the session. In the case of the dashboard, this results in an error that pops up for the user.
• Ratatui can't handle ANSI, so now the color_eyre output is correctly converted into a Text widget.
• The dashboard now takes an impl AsyncRead along with the impl Writer that it used to. This required changing the stdin reader in the dashboard dev command.
• channel_eof now correctly only closes the channel it was meant for and not the entire session (especially if a dashboard was running).
• As data is now owned by the request that created it, the session level data handler only tracks total bytes.