Epic #4192

Description

• Given the changes done in the API story ([atc/api] Increase scope of Admin privilege #4193) add some tests to ensure the fly cli functions as expected for an admin.
• This issue is to target commands that a super-admin can run without logging in to a team, i.e. concourse-wide commands. Go through all the commands in the green rows from this spreadsheet: https://docs.google.com/spreadsheets/d/1cXP7wRLX45hhjR8W78l6oFvs7rwDifg3PBE_u1P80d8/edit#gid=0

Acceptance Criteria

• All fly actions work for the admin
• Have test cases to verify all these actions