[SDKs] Provide a CLI tool to add files to an existing collection
Functional requirements: with a single shell command, the user can add one or more files to an existing collection.
This could be an extension to
arv keep put, like a switch
--add-to [collection UUID], or a new subcommand.
TBD: If the user runs
arv keep put --project-uuid [project] --name [existing collection name], should that add to the existing collection, or continue with the current "ensure unique name" behavior?