Use the CarLI command line application framework.

[kherge]

The following checks have been done.

• I could not find another enhancement request that covers what I need.
• This request does not cover existing functionality.

What existing feature needs to be enhanced?

The application infrastructure.

What problem is being solved?

aws-login directly owns responsibility for how the application should be designed.

How would you like to see this problem solved?

Delegate this to a library dedicated for it, and possibly benefit from improvements made to the library over time.

Some additional context.

I am mostly dogfooding CarLI.