vicky-cli: Basic functionality

[johannwagner]

We probably need a basic CLI tool to interact with Vicky.
This can be used by a user (authentication via OIDC) or a machine.

• We want this as a seperate binary, which creates a config file in a good location.
• We want to be able to login to a specific vicky instance via the CLI.
• We want to be able to switch contexts between different logins and instances, e.g lab and production.
• We want to support an authentication via OAuth2 Device Flow for users.
• We want to support a static authentication for machines (to be discussed, machine authentication is probably a more complex topic)
• We want to be able to do the basic API functionalities via the cli, e.g. create a task, list tasks, etc.
• We want to get the raw output on request.
• We want to have a basic human-readable output if the command fits.
• We want a version command