Resolve "Separate `view code` permission from `download code`..."

What does this MR do and why?

Create a view_code permission for viewing code only

• enable view_code for users that can download_code
• prevent users with view_code only from pulling/downloading repositories

Contributes to: #376180 (closed)

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 #376180 (closed)