[DevOps Adoption] Add Codeowners to the adoption table (FE)

Overview

This is the front end issue for #326008 (closed).

Codeowners is an important piece of the code review process in GitLab. It can help identify who should review contributions to a file or repository and can be used to establish a merge request approval process. In customer interviews so far, this is one of the top most requested features that users would like to see in the adoption table. (Requests being tracked here)

Proposal

Add the codeowners feature to the Dev tab in the DevOps adoption table.

Requirements

• Add to the group-level and instance-level feature
• Add a tooltip explaining how Codeowners adoption is measured
• Add Codeowners to the list of features in the user documentation