Adding Format Output to CLI

[fabianbaier]

What would you like to be added:

I'd like to have the option to determine how the output of the CLI should look like. Right now we just fmt.Println but what's actually needed is similar like in kubectl itself the option to decide how the output should look like, e.g.: kubectl kudo get instance kafka -o yaml

Why is this needed:

This helps not just for testing the CLI behavior but also gives more options in how to format or sort the output of certain commands. It should be closer to kubectl itself ( see also https://kubernetes.io/docs/reference/kubectl/overview/#output-options ).

[kensipe]

We need to be able to specify format type -o yaml and -o json

[alenkacz]

We've partially added it to some commands, let's rather open an issue per-command than have this big umbrella issue