Add role to group access token audit event

What does this MR do and why?

Adds the role to the audit event for Group access token creation.

Related: Add group level access token UI (!77449 - merged)

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Create a group access token using UI
2. Review the Group audit events