feat: Support for start time in read changes request

[ryanpq]

Description

Pulls updates from sdk-generator after latest release and adds support for start time in read changes

References

https://github.com/openfga/sdk-generator/pull/455 https://github.com/openfga/sdk-generator/pull/420 https://github.com/openfga/sdk-generator/pull/398

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