Stream command output

[braheezy]

When I first wrote the app, I had the idea that when the user selects a Vagrant command to run, instead of just showing a spinner, they would get a Viewport where the actual STDOUT/STDERR from the Vagrant command was streamed in line by line, as they were printed. Unfortunately, I never got it working and decided to remove it as a requirement so I could focus on the rest of the app's functionality.

This code at the state of this commit is the closest I got: 0af9c31

This concept is discussed more here: charmbracelet/bubbles#294

[stjohnfinn]

I would recommend having this be a feature you can turn on or off. Maybe add an input like "v" for verbose or "d" for debug. Turns on verbose output. Some users will like this and others won't.