feat: add logout function

[joshua-mo-143]

• add logout function for CLI

Reference: issue #594

Current queries:

• api_key is currently defined as a String type, which means I've had to set the API key in the logout function as an empty string. This technically works, but I'm wondering if it's more correct to set it as None?

[oddgrd]

Nice! While it does work, I think your hunch is correct, it would be better to not just set it to an empty string. I'm thinking we could either change the set_api_key function to take an Option<ApiKey>, or we could add a new method, something like clear_api_key. I'm not quite sure what I would prefer 😄 Maybe you can try it out and see what feels best?

[joshua-mo-143]

Nice! While it does work, I think your hunch is correct, it would be better to not just set it to an empty string. I'm thinking we could either change the set_api_key function to take an Option<ApiKey>, or we could add a new method, something like clear_api_key. I'm not quite sure what I would prefer 😄 Maybe you can try it out and see what feels best?

I decided to add a clear_api_key function in the end since I think that makes more sense for the purpose of modularity, in case we need to use it anywhere else.

[oddgrd]

LGTM, thanks!