Replace admin group, project, and topic avatars with pajamas component

What does this MR do and why?

Describe in detail what your merge request does and why.

Migrates avatars in admin views for groups, projects, and topics to use the pajamas component.

Makes styles consistent between all three.

Matches avatar size with users view in the same area

Screenshots or screen recordings

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Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

• Have an instance with at least 1 project, group, and topic.
• Check the avatars at the following pages
  • http://127.0.0.1:3000/admin/projects
  • http://127.0.0.1:3000/admin/groups
    • Click on a group title to go to the group detail page
  • http://127.0.0.1:3000/admin/topics

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.