Extract User Avatars into Component

[marcoroth]

We have a bunch of representations of user avatars, different sizes, some with white borders, some with name initials fallbacks, some with neither. I think it would make sense to extract a ViewComponent for the avatars so we have one representation we can use throughout the app.

Ideally we could even fetch the profile image from somewhere else (like LinkedIn, X, Bsky) in addition to just GitHub and maybe incorporate #330.