Implement support of remote TTY

[wayerr]

To evaluate approach to add remote TTY via our HTML UI. Note that it may require specific options for run containers & etc.

[wayerr]

as TTY in browser emulator we can use below project:
https://chromium.googlesource.com/apps/libapps/+/master/hterm

also the https://github.com/krishnasrinivas/wetty/blob/master/public/wetty/wetty.js - provide example usage

[wayerr]

Add test page with TTY to any container. Implementation based on https://xtermjs.org/

For 'line spacing issue' see xtermjs/xterm.js#475

[Anselm21]

Please, provide some backend description. At this moment have no idea, what should be done in terms of this task.

[wayerr]

We need some user interface (example provided on page: http://haven/ui/tty.html) which is open from docker container menu and show terminal emulator