Add a menu to pick among multiple files

[plainas]

Preliminary discussion about multiple 'libraries' can be found here:
#7

By introducing an external dependency, this could be trivially.

The three libraries bellow, all provide direct ways to create a TUI select menu. But as far as I can tell, they all will take up the whole screen, which could be confusing/ ugly.

• https://github.com/bchao1/bullet
• https://github.com/IngoMeyer441/simple-term-menu
• https://github.com/mooz/percol

A small popup floating box preserving the current state in the background would be the optimal solution. This shouldn't be too difficult with curses only.

A few TUI libraries might have this functionality, or at least something in those lines is probably implemented somewhere in their code:

• https://urwid.org/index.html
• https://github.com/pfalcon/picotui
• https://github.com/bczsalba/pytermgui
• https://npyscreen.readthedocs.io/index.html