Add blame data to simple viewer

What does this MR do and why?

Add blame data to simple viewer

Changelog: changed

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. Open a listed as fallback file via the repository files browser
2. Click the Blame button in the blob header
3. The blame info should be rendered

Related to #434147 (closed)