Revert "Merge branch 'refactor-avatars' into 'master'"

Purpose of revert

Revert "Merge branch 'refactor-avatars' into 'master'"

This reverts merge request !163899 (merged). There were some CSS changes in that MR that caused visual regressions across avatars on multiple pages. Easiest to revert for now until we can take a closer look at what CSS is needed.

Checklist

• [-] Create an issue to reinstate the merge request and assign it to the author of the reverted merge request.
• [-] If the revert is to resolve a broken 'master' incident, please read through the Responsibilities of the Broken master resolution DRI.
• [-] If the revert involves a database migration, please read through Deleting existing migrations.
• Add the appropriate labels before the MR is created. We can skip CI/CD jobs only if the labels are added before the CI/CD pipeline is created.

Milestone info

• I am reverting something in the current milestone. No changelog is needed, and I've added a ~"regression:*" label.
• I am reverting something in a different milestone. A changelog is needed, and I've removed the ~"regression:*" label.

Related issues and merge requests