docker scout should be able to output data in JSON format

[scott-doyland-burrows]

This is a feature request:

All docker scout commands that are generating output, such as docker scout repo list should be able to display the output in JSON.

Something like:

docker scout repo list --format json

and the extra text such as the What's next message in the example below, should not be included in the JSON.

So just show what is needed, so in this case, the repo name and whether its enabled/disabled.