feat: add emacs keymap mode

[ecklf]

This PR adds a functionality to enable emacs keybindings for navigating the inquire prompts. As it doesn't make sense to enable multiple keybindings at once I extracted it into an enum (which is a breaking change).

[mikaelmello]

Cool idea. Is there any env var standard [1] to set this automatically for end users? We could have it implemented in a way that CLI developers wouldn't need to worry about it.

[1] like https://no-color.org/

[ecklf]

We could check if VISUAL or EDITOR contains "vi" and conditionally set eMacs or vi bindings. Though this may not always be what end users want. Personally, I use vim as my editor, but I prefer eMacs bindings in my cli. I am not sure we can easily extract that information as that’s set up in the users respective shell (zsh/fish/etc.).

[ahstro]

Came here to code this, but glad it already exists! Bumping in hopes this can get merged 💕