Add fork suggestion component

What does this MR do and why?

Adds a fork suggestion component.

Changes in this MR is part of a bigger effort to refactor the blob viewer

description	MR
Add fork suggestion component	This MR
Display fork message when user with minimal access tries to edit a file	Follow-up

Screenshots or screen recordings

No visual changes are expected

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #336052 (closed)