GitLab CLI Authentication
## Problem to Solve
There have been many reported issues (attached to this epic) related to auth across both self-managed and SaaS. Some of them have been resolved, but the logic for authentication and many of the options around the config, flags and environment variables could use more documentation.
## Proposal
We should audit the authentication code to see what issues might be there and look for opportunities, based on the existing issues to improve the process.
epic