BREAKING CHANGE(cli): add user management commands, remove old ones

[xavdid]

Ok! This was a long one.

Refactors the zapier invite command into:

• users:add
• users:remove
• users:get
• users:links

Refactors the zapier collaborate command into:

• team:add
• team:remove
• team:get

As is, the code is fairly repetitive. We're under a little bit of a deadline to get this out, so rather than spend too much time here drying it up, I wanted to get it out the door. In particular, we can probably clean up reused code between the :add commands and how we split api calls between subscribers and collaborators.

For the review, pay particular attention to:

• the help text, ensuring it's clear and not copy-pasted wrong
• the UX of each command. I tried to stay with args and flags instead of interactive, but on one command it was pretty unavoidable. I'm not too bothered though, I honestly really like the interactive experiences.

Also, it would be great to be able to call this.exit() without it looking like an error. The only way I could think to do that is to throw an error with a specific message that we handle at the top-level. I don't love using errors for control flow though. In any case, a simple return from our perform() is perfectly serviceable.

[eliangcs]

The only blocker here is the broken zapier users:links command. I didn't see anything major that needs to be changed in the help text and UX. Good work!

We can leave this in a separate PR, but are you planning to remove zapier invite and zapier collaborate? I think we should because they can be confusing along with the new commands you added.