Support delegations in the CLI

[mnm678]

We added delegation support in #175. Now, it would be great to add support for them to the CLI. I envision something like the following:

• delegate from_role to_role namespace
• Add a parameter to add for the role that the target is added to
• remove-delegation from_role to_role

Feedback would be appreciated, especially on the names

[rdimitrov]

Closing since the code base changed and the goal of the project would be to focus on being a library first and not so much on providing a CLI client.

There might be a CLI based on this, but it will live in a separate repository.

Thanks for raising this 👍