JSON/parseable output for `bootc install *`

[tulilirockz]

This is more of an idea than anything else, but I believe it would be rather interesting to see something like that --progress-fd flag for bootc switch, but with the bootc install commands. That would help out a lot with parsing the output when you are building an installer using bootc install for example.

[cgwalters]

Thanks for filing this! Totally agree. I think it's a dup of #542 though.

Also related is #982 which was a lot harder than I thought.