Export instance parameter values

[ANeumann82]

What would you like to be added: KUDO can use parameter files on install and update with -P.

It would be good to allow KUDO to create such a file with all parameters from an existing instance.

Tasks:

• Find a good place in the CLI to add this. Maybe kudo get parameter-values --instance xyz --output yaml, maybe there's a different command that would be a better match
• Retrieve the specified Instance from the cluster
• Get the list of parameters, format them correctly, and output the list

Why is this needed: To be able to create parameter files that can be used with kudo install -P param-values.yaml