feat: Replace `render` with `TemplateResponse` in admin views

Description

As requested in #1448 and common practice in the Django admin, this PR makes the admin views return a TemplateResponse.

[x] I have opened this pull request against master
[ ] I have added or modified the tests when changing logic
[x] I have followed the conventional commits guidelines to add meaningful information into the changelog
[x] I have read the contribution guidelines and I have joined #workgroup-pr-review on Slack to find a “pr review buddy” who is going to review my pull request.