Add Terminal Reset Helper

This came out of the issue filed over at dialoguer: https://github.com/console-rs/dialoguer/issues/294

The TLDR is that when the application terminates in unexpected ways (or really just ctrl+c) it's pretty easy for the terminal to be left in an unfortunate state. While there might be ways in which APIs can be restructured to cause this less, this is generally quite unfortunate and too easy to cause.

It also will in most cases require either using raw inputs to ensure that ctrl+c is manually handled on all inputs to reset the terminal state locally or (more correctly) to handle cltr+c globally. The latter however requires the user to be involved here as there can really only be one handler via the ctrlc crate or similar.

As a strawman proposal I'm considering adding a helper that people can put into their own ctrlc handlers which resets the terminal back to the state it was in when the application was started.

fn main() {
    let state = console::capture_terminal_state();
    ctrlc::set_handler(move || {
        state.restore();
        // ...
    });
    // stuff happens here
}

Start by reading the linked dialoguer issue and the terminal-state handling around the proposed capture_terminal_state entry point. Clarify how terminal state is captured and restored when a ctrlc handler invokes state.restore(); done should include a documented helper behavior and validation that it restores the startup state.