feat: improvements to OpenTelemetry metrics

[evansims]

Description

This PR updates the changes made in #94 to support a number of new and overlook attributes previously not implemented, and improves clarity in the wording of descriptions. It also updates the attribute naming convention based on feedback.

References

Generated from https://github.com/openfga/sdk-generator/pull/402

Review Checklist

• [x] I have clicked on "allow edits by maintainers".
• [x] 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]
• [x] The correct base branch is being used, if not main
• [x] I have added tests to validate that the change in functionality is working as expected