Fix the /projects/:id/repository/files/:file_path/raw endpoint to handle dots in the file_path…

What does this MR do?

This allows to make API requests for raw files that contain a . in the :file_path.

Are there points in the code the reviewer needs to double check?

no breaking changes made

Why was this MR needed?

API calls with a . in the :file_path would return a 404

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

Closes #31470 (closed)