Add tty-write command

[joelim-work]

Based on discussion in #1943 (comment).

This command offers a synchronized way to write to /dev/tty.

Example usage:

cmd on-cd &{{
    lf -remote "send $id tty-write \"\033]0;$PWD\007\""
}}

cmd on-init :{{
    on-cd
}}

[Kuchteq]

Could you modify the example given in the documentation about setting the terminal title to the working directory with this method?

cmd on-cd &{{
    lf -remote "send $id tty-write \"\033]0;$PWD\007\""
}}

The one that says:

If you want to print escape sequences, you may redirect printf output to /dev/tty.

[joelim-work]

@Kuchteq I missed that, thanks! I see that there's similar examples in the wiki too, so I will update those as well.