Improvement: Switch to notcurses for terminal LEM

[cianoc]

This is more of an aspiration as a lot of things would need to happen for this to be possible, but curses is an old and limited tui library. Notcurses supports recent terminal advances (Kitty images, better support for the keyboard, animation) and works well in modern terminals (Kitty, wezterm, etc). This would also allow the terminal Lem to be more feature complete compared to the webview version.

There isn't currently a Common Lisp FFI library for notcurses. So this would have to happen first, but the API is fairly small:
https://notcurses.com//