[core] Add CLI commands for listing and inviting users

[rexxars]

Patches one of my long time pet peeves - not being able to invite people from the CLI.

Invite

~/my-studio$ sanity help users invite
usage: sanity users invite [EMAIL]

   Invite a new user to the project

Options
  --role Role to invite the user as

Examples
  # Invite a new user to the project (prompt for details)
  sanity users invite

  # Invite user with email "pippi@sanity.io" to the project, prompt for role
  sanity users invite pippi@sanity.io

  # Invite user with email "pippi@sanity.io" to the project, as adminisistrator
  sanity users invite pippi@sanity.io --role administrator

List

~/my-studio$ sanity help users list
usage: sanity users list

   List all users of the project

Options
  --no-invitations Don't include pending invitations
  --no-robots Don't include robots (token users)
  --sort <field> Sort users by specified column: id, name, role, date
  --order <asc/desc> Sort output ascending/descending

Examples
  # List all users of the project
  sanity users list

  # List all users of the project, but exclude pending invitations and robots
  sanity users list --no-invitations --no-robots

  # List all users, sorted by role
  sanity users list --sort role

[kmelve]

You and me both

1. Should it be sanity users in plural (we have documents, projects, versions in plural already)?
2. Should we ship this without sanity user(s) list

I also wonder if it's more correct to have it be sanity user(s) invite since that's actually what we do by running this command. add would have been more correct if we were actually making a user account from this command.

[rexxars]

1. I wish we picked up on this sooner. We also have dataset, hook in singular. Maybe we can rename/deprecate to one form. Should it be singular or plural? 🤔
2. MVP. This still provides value without a list command.
3. Invite works for me 🤷‍♂

[kmelve]

1. I think that plural makes sense in most cases since there's a higher chance that you'll be having more than one user, dataset, hook, token, etc.
2. Ok then!
3. I think we should go with invite then

[kmelve]

I've added suggestions for rephrasing etc.

[rexxars]

• Changed from user to users
• Changed from add to invite
• Added users list command

Could use a new review!

[kmelve]

Tested locally and it works like a charm!