ListUsers exclusion

[willvedd]

Description

Adding support for exclusion rewrites in ListUsers via the but not operator.

To achieve this, we need to expand both parts of the rewrite, the base and subtract. .The base is the left-portion of the but not operator that must evaluate true. The subtract is the right-portion that much evaluate false. First, all the subjects that evaluate true to the base are iterated through and cross-checked against the subtract subjects. If subjects that are only present in the base and not the subtract are returned on the channel.

References

• Sibling PR (intersection): ListUsers intersection #1467
• Parent PR: ListUsers API #1428

Review Checklist

• I have clicked on "allow edits by maintainers".
• I have added documentation for new/changed functionality in this PR or in a PR to openfga.dev [Provide a link to any relevant PRs in the references section above]
• The correct base branch is being used, if not main
• I have added tests to validate that the change in functionality is working as expected