Get to full Bun compatability

[syhner]

Some features were removed in the bun branch to get things working. These features are desired, so we will need to get these working / made compatible. There is some context given in the commit messages. From highest to lowest priority:

• [ ] Working Docker images (commit where related files were changed)
• [ ] Working unit tests when next-auth is enabled (may require mocking 'next-auth' like in the main branch)
• [ ] Working component tests with React Testing Library (commit where related files were changed)
• [ ] Working MDX components (commit where related files were changed)
• [ ] Works as a Progressive Web App (commit where related files were changed)